I really need some criticism on my hombrew monster. Please tell me if you think it is too strong and what changes I should make if any. I have taken heavy inspiration from the demon slayer manga as you may or may not be able to tell. I plan for the encounter to be with a 4 group party of level 20 adventures and several NPC's there to help.
If sokushi isn't in sun light or running water, he can use his action to polymorph into a Tiny bat, a Medium wolf, a Medium cloud of mist, a Large abomination, or back into his true form.
While in bat form, sokushi can't speak, his walking speed is 5 feet, and he has a flying speed of 30 feet. His statistics, other than his size and speed, are unchanged. Anything he is wearing transforms with him, but nothing he is carrying does. He reverts to his true form if he dies.
While in wolf form, sokushi can’t speak and his walking speed is 40 feet. His statistics, other than his speed, are unchanged. Anything he is wearing transforms with him, but nothing he is carrying does. He reverts to his true form if he dies.
While in mist form, sokushi can't take any actions, speak, or manipulate objects. He is weightless, has a flying speed of 20 feet, can hover, and can enter a hostile creature's space and stop there. In addition, if air can pass through a space, the mist can do so without squeezing, and he can't pass through water. He has advantage on Strength, Dexterity, and Constitution saving throws, and he is immune to all nonmagical damage, except the damage he takes from sunlight.
While in abomination form, sokushi has advantage on Strength checks and saving throws, is resistance to all damage types except fire, force, psychic, and radiant damage, as well as acid damage from holy water, and a fly speed of 40 feet. Anything he is wearing transforms with him, but nothing he is carrying does.
Legendary Resistance (3/Day).
If sokushi fails a saving throw, he can choose to succeed instead.
Misty Escape.
When he drops to 0 hit points outside his resting place, sokushi transforms into a cloud of mist (as in the Shapechanger trait) instead of falling unconscious, provided that he isn't in sunlight or running water. If he can't transform, he is destroyed.
While he has 0 hit points in mist form, sokushi can't revert to his vampire form, and he must reach his resting place within 2 hours or be destroyed. Once in his resting place, he reverts to his vampire form. He is then paralyzed until he regains at least 1 hit point. After spending 1 hour in his resting place with 0 hit points, sokushi regains 1 hit point.
Regeneration.
Sokushi regains 30 hit points at the start of his turn if he has at least 1 hit point and isn't in sunlight or running water. If sokushi takes radiant damage or damage from holy water, this trait doesn't function at the start of sokushi's next turn.
Spider Climb.
Sokushi can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check.
Vampire Weaknesses.
Sokushi has the following flaws:
Forbiddance. Sokushi can't enter a residence without an invitation from one of the occupants.
Harmed by Running Water. Sokushi takes 20 acid damage if he ends his turn in running water.
Stake to the Heart. If a piercing weapon made of wood is driven into sokushi's heart while he is incapacitated in his resting place, sokushi is paralyzed until the stake is removed.
Sunlight Hypersensitivity. Sokushi takes 20 radiant damage when he starts his turn in sunlight. While in sunlight, sokushi has disadvantage on attack rolls and ability checks, and he cannot maintain concentration on see through world.
Action Surge (2/Day).
Sokushi can push himself beyond his normal limits for a moment. On his turn, he can take one additional action. He can only use this feature once on the same turn.
Strength Before Oblivion (1/Day).
If sokushi takes damage that reduces him to 0 hit points, he can use his reaction to delay misty escape, and he can immediately take an extra turn. When the extra turn ends, sokushi turns into mist as the misty escape trait if he still has 0 hit points.
Unreal Speed.
Sokushi has advantage on Dexterity saving throws, and he has an additional action on each of his turns. The action can be used only to take the Attack (one weapon attack only), Dash, Disengage, Hide, or Use an Object action. When Sokushi uses the Dash action, difficult terrain doesn't cost him extra movement on that turn. When sokushi makes a melee attack against a creature, he does not provoke opportunity attacks from that creature for the rest of the turn, whether he hit or not.
Evasion.
When sokushi is subjected to an effect that allows him to make a Dexterity saving throw to take only half damage, he instead takes no damage if he succeeds on the saving throw, and only half damage if he fails.
Actions
Multiattack (Vampire Form Only).
Sokushi makes six attacks, only one of which can be a bite attack.
Black Blade +3 (Vampire Form Only).
Melee Weapon Attack: +20 to hit, reach 5 ft., one target. Hit: 14 (1d10 + 8) slashing damage plus 11 (2d10) force damage. While sokushi has the blade drawn, he has advantage on Saving Throws against Spells and other magical Effects. This attack scores a critical hit on a roll of 18 or 20.
Fire Bolt.
Ranged Spell Attack: +13 to hit, range 120 ft., one target. Hit: (4d10) fire damage.
Unarmed Strike (Vampire Form Only).
Melee Weapon Attack: +17 to hit, reach 5 ft., one creature. Hit: 14 (1d10 + 8) bludgeoning damage. Instead of dealing damage, sokushi can grapple the target (escape DC 20).
Bite (Bat, Wolf, Abomination or Vampire Form Only).
Melee Weapon Attack: +15 to hit, reach 5 ft., one willing creature, or a creature that is grappled by sokushi, incapacitated, or restrained. Hit: 9 (1d6 + 8) piercing damage plus 10 (3d6) necrotic damage, or 14 (2d8 + 8) piercing damage, plus 21 (6d6) necrotic damage in abomination form. The target's hit point maximum is reduced by an amount equal to the necrotic damage taken, and sokushi regains hit points equal to that amount. The reduction lasts until the target finishes a long rest. The target dies if this effect reduces its hit point maximum to 0. A humanoid slain in this way and then buried in the ground rises the following night as a vampire spawn under sokushi's control.
Claws (Abomination form Only).
Melee Weapon Attack: +12 to hit, reach 10 ft., one target. Hit: 14 (2d8 + 5) slashing damage, and the target is grappled (escape DC 20).
Translucent Vision.
Sokushi's strong eyes grant him superhuman kinetic vision allowing him to see the muscles, blood flow, and joint movement of his opponent. Sokushi fixates on one creature within 60 ft. Until sokushi switches his fixation as a bonus action or loses his concentration, he has advantage on all attacks against that creature and on any saving throws that creature causes him to make. Any creature sokushi is concentrating on has disadvantage on all attack rolls made against him.
Charm.
Sokushi targets one humanoid he can see within 30 ft. of him. If the target can see sokushi, the target must succeed on a DC 22 Wisdom saving throw against this magic or be charmed by sokushi. The charmed target regards sokushi as a trusted friend to be heeded and protected. Although the target isn't under sokushi's control, it takes his requests or actions in the most favorable way it can, and it is a willing target for sokushi's bite attack. Each time sokushi or sokushi's companions do anything harmful to the target, it can repeat the saving throw, ending the effect on itself on a success. Otherwise, the effect lasts 24 hours or until sokushi is destroyed, is on a different plane of existence than the target, or takes a bonus action to end the effect.
Area Slash (Recharge 6).
Sokushi focuses the energy in his sword and makes 6 large purple energy slashes in a 60-foot cone. Each creature in the cone must make a DC 25 Dexterity saving throw, taking 33 (6d10) slashing damage and 33 (6d10) force damage on a failed save, or half as much damage on a successful one.
Bonus Actions
Fighting Spirit 3/Short Rest.
Kamisori gives himself advantage on all weapon attack rolls until the end of the current turn. When kamisori does so, he also gains 15 temporary hit points.
Quickened Action.
Sokushi takes the dash, disengage, dodge action, or makes two more melee attacks. Sokushi can only make two more melee attacks if he has already taken the attack action.
Reactions
Slow Fall.
Sokushi reduces any falling damage he takes by 85.
Perfect Dodge.
Sokushi takes no damage from any attack that deals damage, and can move up to half his speed.
Legendary Actions
Sokushi can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another creature's turn. Sokushi regains spent legendary actions at the start of his turn.
Move.
Sokushi moves up to his speed without provoking opportunity attacks.
Strike.
Sokushi makes one attack.
Bite (Costs 2 Actions).
Sokushi makes one bite attack.
Spinning Slash (Cost 2 Actions).
Sokushi spins his sword around. All creatures within 5 feet of him must make a DC 25 dexterity saving throw taking 19 (2d10 + 8) slashing damage plus 22 (4d10) force damage and be knocked prone on a failed save, or take half damage on a successful one and be knocked back 5 feet.
This monster would be impossible to kill if played intelligently, but could also be impossible to lose to at the same time. It would also be incredibly annoying to run if using a grid / map because of the necessity of a truly enormous map.
Here are the biggest issues:
Cannot be killed:
Sokushi can move 650 ft per round without provoking attacks of opportunity, without using his action. This means he can (and should) run 300ft away from the players such that they are incapable of hitting him with anything other than a longbow with sharpshooter, then run 300 ft back hit the players and run 300 ft away again.
With such high saving throws + legendary resistance he will never fail a saving throw. Thus conditions are irrelevant, save-or-suck spells are irrelevant and with his Evasion everything that uses a Dex save it irrelevant.
Given his regeneration capability: 50 hp per round, high saves, escape ability and extremely high AC (even with Advantage an archer with a +3 longbow and archery fighting style has less than a 50% chance to hit him) it would be essentially impossible to kill him.
Cannot be lost to:
He has extremely limited ranged options, and is crippled while flying. Thus the party need to only take to the air to be generally untouchable by him.
In addition to what is mentioned above, the stat block is kind of boring. It is extremely powerful, but at high level play, this really just bogs down combat and makes it difficult to balance. In my experience, high-level encounters are much more interesting if you add some sort of "gimmick" to the fight instead of using purely large numbers. You seem to be aiming for a vampire with a powerful movement theme. When planning the fight, do it in some sort of arena or huge cave with walls and a ceiling. Enough so that he can move around, but not so much it's impossible for the PC's to catch him. Add a jump ability to deal with flying PC's. You should remove the Charm effect or give it a repeated save any time the target takes damage, as it is an extremely unfun "pass or die" ability that your players will likely get mad at you for. During the battle, use the hit&run tactics described above that make him impossible to hit. Greatly nerf his damage and to hit scores so that he is not imminently deadly, but to be dealt with over a long series of rounds. The end goal here is to create an enemy impossible to hit, but not immediately deadly; it won't TPK in six rounds, but killing it in that time should be nearly impossible. I would then add a mechanic to the fight that would allow PC's to open up holes in the ceiling to sunlight during the fight. The exact mechanism for doing this could vary, but it should be made apparent to the players at the start of the fight (maybe one of the NPC's notices something). Then, change his sunlight sensitivity to a custom effect instead of the standard damage per round and disadvantage. as sun begins to pour into the chamber, first in small amounts, then more, make his defensive stats (such as his saving throws and AC) significantly lower, gradually nerf and remove his movement buffs, and weaken then remove his regen and his bite healing. Make his max HP lower as he takes damage from sunlight, but cap the reduction for each "stage" of the fight. As the end of the fight grows near, greatly increase his damage for a final nova when he gets low. you get describe this as a "rage" when he is weakened.
The end goal of playing the fight this way is to create an interesting and engaging battle against an enemy that feels like an insurmountable force whilst still giving the PC's a fighting chance. Instead of blasting at each other for 3-4 rounds, this should feel more like trying to solve a puzzle against a ticking clock as the PC's hitpoints slowly whittle down with every round, until they finally solve the puzzle and have to win in a final fight against a weakened, but still very powerful, vampire.
P.S. I would recommend removing the misty escape, unless you plan on using him as a BBEG in an extended campaign, which I'm assuming your not because your PC's are 20th level. If this is a finale or one-shot, give your PCs the satisfaction of confirming the kill at the end of the battle.
Agreed. High level combat shouldn't be just smashing two sets of big numbers against each other. That's just not very interesting. The proposed statblock is also extremely long, many parts of which are redundant or not particularly useful. Below I've taken most of the same abilities / design and just streamlined it down so combat doesn't drag while the DM looks through the whole statblock for what they want.
Sokushi/Tsuki Ereganto
Medium undead (shapechanger), lawful evil
Armor Class: 27 (natural armor)
Hit Points: 462 (37d10 + 259)
Speed: 120 ft.
STR 24 (+7) DEX 26 (+8) CON 24 (+7) INT 19 (+4) WIS 22 (+6) CHA 21 (+5)
Legendary Resistance (3/Day). If sokushi fails a saving throw, he can choose to succeed instead.
Magic Resistance. Sokushi had advantage on saving throws against spells and magical effects.
Spider Climb. Sokushi can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check.
Sunlight Hypersensitivity. Sokushi is blinded for 1 round and takes 20 radiant damage when he enters an area of sunlight or starts his turn there.
Unreal Speed. Sokushi had advantage on Dexterity saving throws and takes 0 damage on a success and only 1/2 damage on a failure. His movement does not provoke attacks of opportunity, and difficult terrain doesn't cost him extra movement.
Actions
Multiattack. Sokushi makes six attacks with his sword/unarmed strike and one bite attack
Black Blade.Melee Weapon Attack: +16 to hit, reach 5 ft., one target. Hit: 14 (1d10 + 8) slashing damage plus 11 (2d10) force damage.
Unarmed Strike. Melee Weapon Attack: +16 to hit, reach 5 ft., one creature. Hit: 14 (1d10 + 8) bludgeoning damage. Instead of dealing damage, sokushi can grapple the target (escape DC 22).
Bite. Melee Weapon Attack: +16 to hit, reach 5 ft., one willing creature, or a creature that is grappled by sokushi, incapacitated, or restrained. Hit: 14 (2d8 + 8) piercing damage, plus 21 (6d6) necrotic damage. The target's hit point maximum is reduced by an amount equal to the necrotic damage taken, and sokushi regains hit points equal to that amount. The reduction lasts until the target finishes a long rest. The target dies if this effect reduces its hit point maximum to 0. A humanoid slain in this way and then buried in the ground rises the following night as a vampire spawn under sokushi's control.
Area Slash (recharge 5-6). Sokushi focuses the energy in his sword and makes 6 large purple energy slashes in a 60-foot cone. Each creature in the cone must make a DC 22 Dexterity saving throw, taking 33 (6d10) slashing damage and 33 (6d10) force damage on a failed save, or half as much damage on a successful one.
Bonus Actions
Translucent Vision. Sokushi's strong eyes grant him superhuman kinetic vision allowing him to see the muscles, blood flow, and joint movement of his opponent. Sokushi fixates on one creature within 60 ft that he can see. He has advantage on all attacks against that creature and that creature has disadvantage on all attack rolls made against him as long as he can see that creature or until he uses this feature again or until his concentration is broken as if he was concentrating on a spell.
Fighting Spirit (if Sokushi has fewer than 50% of his maximum hit points remaining). Sokushigives himself advantage on all weapon attack rolls until the end of the current turn.
Quickened Action. Sokushi takes the dash, disengage, or dodge action.
Reactions
Slow Fall. Sokushi reduces any falling damage he takes by 85.
Perfect Dodge. When Sokushi is targeted by an attack and his speed is > 0 ft, he can leap up to 15 ft out of the way causing the attack to miss.
Legendary Actions
Sokushi can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another creature's turn. Sokushi regains spent legendary actions at the start of his turn.
Move. Sokushi moves up to his speed.
Bite (Costs 2 Actions). Sokushi makes one bite attack.
Spinning Slash (Cost 2 Actions). Sokushi spins his sword around. All creatures within 5 feet of him must make a DC 22 Dexterity saving throw taking 17 (3d10) slashing damage plus 17 (3d10) force damage and be knocked prone on a failed save, or take half damage on a successful one.
I cannot thank you enough for the revision on the stat block. You guys really helped put this into perspective. (I am running my first ever high level campaign)
The Tarrasque is actually an outlier. Ever CR 30 monster realeased after the MM (there have been 3) has 5 Legendary Resistance. The Tarrasque is largely regarded to be the weakest of the four because it has no ranged attack or fly speed.
Rollback Post to RevisionRollBack
I write homebrew and don't publish it. (evil, I know)
You once met Bob the eternal and, rather than attacking him as if he was a monster, forged a friendship with him. Bob is a being of shadow, built out of cuboidal shapes and with a glowing white smile that always seems to brighten your day. He enjoys practical jokes and so has taught you some of the tricks that he uses in the hope you could someday join him. Bob does not tend to meet many people who seem friendly so, unlike some warlocks, you are almost definitely of great value to your patron.
Expanded spell list
Bob the eternal has given you a few more options for when he gives you spells! here they are:
1st level feature: Bob believes that to forge a friendship, you need to be able to be there with him and so - to preserve your life - he grants you the ability to resurrect yourself. Once per short rest, when reduced to 0 hitpoints or killed outright, you may instead be on half of your hitpoint max, rounded down. Bob has, however, overlooked that your mortal body is not well equipped to handle such powerful forces, meaning that whenever you use this ability, you gain 1 level of exhaustion.
Choice redirect
6th level feature:
When you are targeted by an attack, you may use your reaction to change the original target of the attack to any friendly creature within 60ft of you. You may do this {{proficiency}} times per short or long rest.
Modify outcomes
10th level feature: When a creature within 60ft of you succeeds on a saving throw, attack roll or ability check you may use your reaction to instead decide that they failed. You may do this an amount of times per short rest equal to your level divided by five, rounded up.
I really need some criticism on my hombrew monster. Please tell me if you think it is too strong and what changes I should make if any. I have taken heavy inspiration from the demon slayer manga as you may or may not be able to tell. I plan for the encounter to be with a 4 group party of level 20 adventures and several NPC's there to help.
Sokushi/Tsuki Ereganto
Medium undead (shapechanger), lawful evil
Armor Class
30 (natural armor)
Hit Points
462 (37d10 + 259)
Speed
130 ft.
STR
24 (+7)
DEX
26 (+8)
CON
24 (+7)
INT
19 (+4)
WIS
22 (+6)
CHA
21 (+5)
Saving Throws
Str +16, Dex +17, Con +16, Int +13, Wis +15, Cha +14
Skills
Acrobatics +17, Athletics +16, Insight +15, Perception +15, Persuasion +14, Stealth +17
Damage Resistances
necrotic; bludgeoning, piercing, and slashing from nonmagical attacks
Senses
blindsight 10 ft., darkvision 120 ft., passive Perception 25
Languages
All
Challenge
30 (155,000 XP)
Shapechanger.
If sokushi isn't in sun light or running water, he can use his action to polymorph into a Tiny bat, a Medium wolf, a Medium cloud of mist, a Large abomination, or back into his true form.
Legendary Resistance (3/Day).
If sokushi fails a saving throw, he can choose to succeed instead.
Misty Escape.
When he drops to 0 hit points outside his resting place, sokushi transforms into a cloud of mist (as in the Shapechanger trait) instead of falling unconscious, provided that he isn't in sunlight or running water. If he can't transform, he is destroyed.
Regeneration.
Sokushi regains 30 hit points at the start of his turn if he has at least 1 hit point and isn't in sunlight or running water. If sokushi takes radiant damage or damage from holy water, this trait doesn't function at the start of sokushi's next turn.
Spider Climb.
Sokushi can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check.
Vampire Weaknesses.
Sokushi has the following flaws:
Action Surge (2/Day).
Sokushi can push himself beyond his normal limits for a moment. On his turn, he can take one additional action. He can only use this feature once on the same turn.
Strength Before Oblivion (1/Day).
If sokushi takes damage that reduces him to 0 hit points, he can use his reaction to delay misty escape, and he can immediately take an extra turn. When the extra turn ends, sokushi turns into mist as the misty escape trait if he still has 0 hit points.
Unreal Speed.
Sokushi has advantage on Dexterity saving throws, and he has an additional action on each of his turns. The action can be used only to take the Attack (one weapon attack only), Dash, Disengage, Hide, or Use an Object action. When Sokushi uses the Dash action, difficult terrain doesn't cost him extra movement on that turn. When sokushi makes a melee attack against a creature, he does not provoke opportunity attacks from that creature for the rest of the turn, whether he hit or not.
Evasion.
When sokushi is subjected to an effect that allows him to make a Dexterity saving throw to take only half damage, he instead takes no damage if he succeeds on the saving throw, and only half damage if he fails.
Actions
Multiattack (Vampire Form Only).
Sokushi makes six attacks, only one of which can be a bite attack.
Black Blade +3 (Vampire Form Only).
Melee Weapon Attack: +20 to hit, reach 5 ft., one target. Hit: 14 (1d10 + 8) slashing damage plus 11 (2d10) force damage. While sokushi has the blade drawn, he has advantage on Saving Throws against Spells and other magical Effects. This attack scores a critical hit on a roll of 18 or 20.
Fire Bolt.
Ranged Spell Attack: +13 to hit, range 120 ft., one target. Hit: (4d10) fire damage.
Unarmed Strike (Vampire Form Only).
Melee Weapon Attack: +17 to hit, reach 5 ft., one creature. Hit: 14 (1d10 + 8) bludgeoning damage. Instead of dealing damage, sokushi can grapple the target (escape DC 20).
Bite (Bat, Wolf, Abomination or Vampire Form Only).
Melee Weapon Attack: +15 to hit, reach 5 ft., one willing creature, or a creature that is grappled by sokushi, incapacitated, or restrained. Hit: 9 (1d6 + 8) piercing damage plus 10 (3d6) necrotic damage, or 14 (2d8 + 8) piercing damage, plus 21 (6d6) necrotic damage in abomination form. The target's hit point maximum is reduced by an amount equal to the necrotic damage taken, and sokushi regains hit points equal to that amount. The reduction lasts until the target finishes a long rest. The target dies if this effect reduces its hit point maximum to 0. A humanoid slain in this way and then buried in the ground rises the following night as a vampire spawn under sokushi's control.
Claws (Abomination form Only).
Melee Weapon Attack: +12 to hit, reach 10 ft., one target. Hit: 14 (2d8 + 5) slashing damage, and the target is grappled (escape DC 20).
Translucent Vision.
Sokushi's strong eyes grant him superhuman kinetic vision allowing him to see the muscles, blood flow, and joint movement of his opponent. Sokushi fixates on one creature within 60 ft. Until sokushi switches his fixation as a bonus action or loses his concentration, he has advantage on all attacks against that creature and on any saving throws that creature causes him to make. Any creature sokushi is concentrating on has disadvantage on all attack rolls made against him.
Charm.
Sokushi targets one humanoid he can see within 30 ft. of him. If the target can see sokushi, the target must succeed on a DC 22 Wisdom saving throw against this magic or be charmed by sokushi. The charmed target regards sokushi as a trusted friend to be heeded and protected. Although the target isn't under sokushi's control, it takes his requests or actions in the most favorable way it can, and it is a willing target for sokushi's bite attack. Each time sokushi or sokushi's companions do anything harmful to the target, it can repeat the saving throw, ending the effect on itself on a success. Otherwise, the effect lasts 24 hours or until sokushi is destroyed, is on a different plane of existence than the target, or takes a bonus action to end the effect.
Area Slash (Recharge 6).
Sokushi focuses the energy in his sword and makes 6 large purple energy slashes in a 60-foot cone. Each creature in the cone must make a DC 25 Dexterity saving throw, taking 33 (6d10) slashing damage and 33 (6d10) force damage on a failed save, or half as much damage on a successful one.
Bonus Actions
Fighting Spirit 3/Short Rest.
Kamisori gives himself advantage on all weapon attack rolls until the end of the current turn. When kamisori does so, he also gains 15 temporary hit points.
Quickened Action.
Sokushi takes the dash, disengage, dodge action, or makes two more melee attacks. Sokushi can only make two more melee attacks if he has already taken the attack action.
Reactions
Slow Fall.
Sokushi reduces any falling damage he takes by 85.
Perfect Dodge.
Sokushi takes no damage from any attack that deals damage, and can move up to half his speed.
Legendary Actions
Move.
Sokushi moves up to his speed without provoking opportunity attacks.
Strike.
Sokushi makes one attack.
Bite (Costs 2 Actions).
Sokushi makes one bite attack.
Spinning Slash (Cost 2 Actions).
Sokushi spins his sword around. All creatures within 5 feet of him must make a DC 25 dexterity saving throw taking 19 (2d10 + 8) slashing damage plus 22 (4d10) force damage and be knocked prone on a failed save, or take half damage on a successful one and be knocked back 5 feet.
This monster would be impossible to kill if played intelligently, but could also be impossible to lose to at the same time. It would also be incredibly annoying to run if using a grid / map because of the necessity of a truly enormous map.
Here are the biggest issues:
Cannot be killed:
Sokushi can move 650 ft per round without provoking attacks of opportunity, without using his action. This means he can (and should) run 300ft away from the players such that they are incapable of hitting him with anything other than a longbow with sharpshooter, then run 300 ft back hit the players and run 300 ft away again.
With such high saving throws + legendary resistance he will never fail a saving throw. Thus conditions are irrelevant, save-or-suck spells are irrelevant and with his Evasion everything that uses a Dex save it irrelevant.
Given his regeneration capability: 50 hp per round, high saves, escape ability and extremely high AC (even with Advantage an archer with a +3 longbow and archery fighting style has less than a 50% chance to hit him) it would be essentially impossible to kill him.
Cannot be lost to:
He has extremely limited ranged options, and is crippled while flying. Thus the party need to only take to the air to be generally untouchable by him.
In addition to what is mentioned above, the stat block is kind of boring. It is extremely powerful, but at high level play, this really just bogs down combat and makes it difficult to balance. In my experience, high-level encounters are much more interesting if you add some sort of "gimmick" to the fight instead of using purely large numbers. You seem to be aiming for a vampire with a powerful movement theme. When planning the fight, do it in some sort of arena or huge cave with walls and a ceiling. Enough so that he can move around, but not so much it's impossible for the PC's to catch him. Add a jump ability to deal with flying PC's. You should remove the Charm effect or give it a repeated save any time the target takes damage, as it is an extremely unfun "pass or die" ability that your players will likely get mad at you for. During the battle, use the hit&run tactics described above that make him impossible to hit. Greatly nerf his damage and to hit scores so that he is not imminently deadly, but to be dealt with over a long series of rounds. The end goal here is to create an enemy impossible to hit, but not immediately deadly; it won't TPK in six rounds, but killing it in that time should be nearly impossible. I would then add a mechanic to the fight that would allow PC's to open up holes in the ceiling to sunlight during the fight. The exact mechanism for doing this could vary, but it should be made apparent to the players at the start of the fight (maybe one of the NPC's notices something). Then, change his sunlight sensitivity to a custom effect instead of the standard damage per round and disadvantage. as sun begins to pour into the chamber, first in small amounts, then more, make his defensive stats (such as his saving throws and AC) significantly lower, gradually nerf and remove his movement buffs, and weaken then remove his regen and his bite healing. Make his max HP lower as he takes damage from sunlight, but cap the reduction for each "stage" of the fight. As the end of the fight grows near, greatly increase his damage for a final nova when he gets low. you get describe this as a "rage" when he is weakened.
The end goal of playing the fight this way is to create an interesting and engaging battle against an enemy that feels like an insurmountable force whilst still giving the PC's a fighting chance. Instead of blasting at each other for 3-4 rounds, this should feel more like trying to solve a puzzle against a ticking clock as the PC's hitpoints slowly whittle down with every round, until they finally solve the puzzle and have to win in a final fight against a weakened, but still very powerful, vampire.
P.S. I would recommend removing the misty escape, unless you plan on using him as a BBEG in an extended campaign, which I'm assuming your not because your PC's are 20th level. If this is a finale or one-shot, give your PCs the satisfaction of confirming the kill at the end of the battle.
I write homebrew and don't publish it. (evil, I know)
Agreed. High level combat shouldn't be just smashing two sets of big numbers against each other. That's just not very interesting. The proposed statblock is also extremely long, many parts of which are redundant or not particularly useful. Below I've taken most of the same abilities / design and just streamlined it down so combat doesn't drag while the DM looks through the whole statblock for what they want.
Sokushi/Tsuki Ereganto
Medium undead (shapechanger), lawful evil
Armor Class: 27 (natural armor)
Hit Points: 462 (37d10 + 259)
Speed: 120 ft.
STR 24 (+7) DEX 26 (+8) CON 24 (+7) INT 19 (+4) WIS 22 (+6) CHA 21 (+5)
Saving Throws: Dex +14, Con +13, Wis +12, Cha +11
Skills Acrobatics: +17, Athletics +16, Insight +15, Perception +15, Stealth +17
Damage Resistances
necrotic; bludgeoning, piercing, and slashing from nonmagical attacks
Senses
blindsight 10 ft., darkvision 120 ft., passive Perception 25
Languages All
CR : 30 (155,000 XP)
Legendary Resistance (3/Day). If sokushi fails a saving throw, he can choose to succeed instead.
Magic Resistance. Sokushi had advantage on saving throws against spells and magical effects.
Spider Climb. Sokushi can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check.
Sunlight Hypersensitivity. Sokushi is blinded for 1 round and takes 20 radiant damage when he enters an area of sunlight or starts his turn there.
Unreal Speed. Sokushi had advantage on Dexterity saving throws and takes 0 damage on a success and only 1/2 damage on a failure. His movement does not provoke attacks of opportunity, and difficult terrain doesn't cost him extra movement.
Actions
Multiattack. Sokushi makes six attacks with his sword/unarmed strike and one bite attack
Black Blade. Melee Weapon Attack: +16 to hit, reach 5 ft., one target. Hit: 14 (1d10 + 8) slashing damage plus 11 (2d10) force damage.
Unarmed Strike. Melee Weapon Attack: +16 to hit, reach 5 ft., one creature. Hit: 14 (1d10 + 8) bludgeoning damage. Instead of dealing damage, sokushi can grapple the target (escape DC 22).
Bite. Melee Weapon Attack: +16 to hit, reach 5 ft., one willing creature, or a creature that is grappled by sokushi, incapacitated, or restrained. Hit: 14 (2d8 + 8) piercing damage, plus 21 (6d6) necrotic damage. The target's hit point maximum is reduced by an amount equal to the necrotic damage taken, and sokushi regains hit points equal to that amount. The reduction lasts until the target finishes a long rest. The target dies if this effect reduces its hit point maximum to 0. A humanoid slain in this way and then buried in the ground rises the following night as a vampire spawn under sokushi's control.
Area Slash (recharge 5-6). Sokushi focuses the energy in his sword and makes 6 large purple energy slashes in a 60-foot cone. Each creature in the cone must make a DC 22 Dexterity saving throw, taking 33 (6d10) slashing damage and 33 (6d10) force damage on a failed save, or half as much damage on a successful one.
Bonus Actions
Translucent Vision. Sokushi's strong eyes grant him superhuman kinetic vision allowing him to see the muscles, blood flow, and joint movement of his opponent. Sokushi fixates on one creature within 60 ft that he can see. He has advantage on all attacks against that creature and that creature has disadvantage on all attack rolls made against him as long as he can see that creature or until he uses this feature again or until his concentration is broken as if he was concentrating on a spell.
Fighting Spirit (if Sokushi has fewer than 50% of his maximum hit points remaining). Sokushi gives himself advantage on all weapon attack rolls until the end of the current turn.
Quickened Action. Sokushi takes the dash, disengage, or dodge action.
Reactions
Slow Fall. Sokushi reduces any falling damage he takes by 85.
Perfect Dodge. When Sokushi is targeted by an attack and his speed is > 0 ft, he can leap up to 15 ft out of the way causing the attack to miss.
Legendary Actions
Move. Sokushi moves up to his speed.
Bite (Costs 2 Actions). Sokushi makes one bite attack.
Spinning Slash (Cost 2 Actions). Sokushi spins his sword around. All creatures within 5 feet of him must make a DC 22 Dexterity saving throw taking 17 (3d10) slashing damage plus 17 (3d10) force damage and be knocked prone on a failed save, or take half damage on a successful one.
Also, CR 30 typically gets 5 legendary resistances.
I write homebrew and don't publish it. (evil, I know)
I mean the tarrasque only has 3
I cannot thank you enough for the revision on the stat block. You guys really helped put this into perspective. (I am running my first ever high level campaign)
The Tarrasque is actually an outlier. Ever CR 30 monster realeased after the MM (there have been 3) has 5 Legendary Resistance. The Tarrasque is largely regarded to be the weakest of the four because it has no ranged attack or fly speed.
I write homebrew and don't publish it. (evil, I know)
Can you criticize this homebrew subclass?
Bob the Eternal (warlock subclass)
You once met Bob the eternal and, rather than attacking him as if he was a monster, forged a friendship with him. Bob is a being of shadow, built out of cuboidal shapes and with a glowing white smile that always seems to brighten your day. He enjoys practical jokes and so has taught you some of the tricks that he uses in the hope you could someday join him. Bob does not tend to meet many people who seem friendly so, unlike some warlocks, you are almost definitely of great value to your patron.
Expanded spell list
Bob the eternal has given you a few more options for when he gives you spells! here they are:
1st
bane , command
2nd
arcanist's magic aura , pass without trace
3rd
slow , water walk
4th
phantasmal killer , dominate beast
5th
mislead , dominate person
Bob is Eternal, you are too
1st level feature:
Bob believes that to forge a friendship, you need to be able to be there with him and so - to preserve your life - he grants you the ability to resurrect yourself. Once per short rest, when reduced to 0 hitpoints or killed outright, you may instead be on half of your hitpoint max, rounded down. Bob has, however, overlooked that your mortal body is not well equipped to handle such powerful forces, meaning that whenever you use this ability, you gain 1 level of exhaustion.
Choice redirect
6th level feature:
When you are targeted by an attack, you may use your reaction to change the original target of the attack to any friendly creature within 60ft of you. You may do this {{proficiency}} times per short or long rest.
Modify outcomes
10th level feature:
When a creature within 60ft of you succeeds on a saving throw, attack roll or ability check you may use your reaction to instead decide that they failed. You may do this an amount of times per short rest equal to your level divided by five, rounded up.
AHAAHAHHAHAHAHHAHAHHAHHAHHAHAHAHAHHAHAHHAHHHAhAHAH INSSANSITY YEAAH
there is a 14th level thing just doesn't appear here and am not sure why
AHAAHAHHAHAHAHHAHAHHAHHAHHAHAHAHAHHAHAHHAHHHAhAHAH INSSANSITY YEAAH
Modify outcomes is utterly broken and will totally destroy your game.