Algorath the Ancient One

Extreme Regeneration: Algorath regenerates 50 (3d20 + 20) hp at the beginning of each of his turns as long as he has at least 1 hp. If Algorath is in his lair, he regenerates an additional 10 hp at the beginning of each of his turns. If Algorath loses a limb or head, it regenerates after 1d4 (-1 if in lair) rounds. If an effect would stop Algorath from regaining hp it instead reduces the amount regained by half. If an effect would stop Algorath from regenerating his limbs or heads it instead takes 1d6 (-1 if in lair) rounds  to regenerate.

Limited Magic Immunity: Unless he wishes to be affected, Algorath is immune to spells of 6th level or lower. Algorath has advantage on saving throws against all other spells and magical effects.

Reflective scales: Any time Algorath is targeted by a Magic missile spell, a line spell, or a spell that requires a ranged Attack roll, roll a d6. On a 1 to 5, Algorath is unaffected. On 6, Algorath is unaffected, and the spell is reflected back at the caster as though it originated from Algorath, turning the caster into the target and dealing double damage.

Keeper of the balance: All damage taken by chaotic evil and lawful good creatures is reduced by 9, all damage taken by chaotic good and lawful evil creatures is reduced by 7, all damage taken by neutral good, neutral evil, lawful neutral and chaotic neutral creatures is reduced by 5.

Spellcasting: Algorath's Spell Save DC is 27 and his spell attack modifier is +19. Algorath has all spells from all classes prepared, he has the following number of spell slots.

1st, 2nd, 3rd, 4th, 5th and 6th level (at will):

7th level (12 slots)

8th level (8 slots)

9th level (4 slots)

10th level (2 slots): Can be used to quicken a spell of 6th level or lower.

11th level (1 slot): Can be used to quicken a spell of 7th level or lower.

12th level (1 slot): Can be used to quicken a spell of 8th level or lower and increases the attack roll or save DC by 1.

13th level (1 slot): Can be used to quicken a spell of 9th level or lower and increases the attack roll or save DC by 2.

Iron Will: When Algorath is subjected to an effect that allows him to make a constitution, intelligence, wisdom, or charisma 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.

Aura of Truth: All creatures within 600ft. of Algorath (including Algorath) are unable to speak a deliberate lie. A creature aware of this effect can avoid answering questions to which it would normally respond with a lie. Such a creature can be evasive in its answers as long as it remains within the boundaries of the truth.

Intense Presence: Hostile creatures that start their turn within 20 ft of Algorath, take 3 (1d6) psychic damage. This damage increases to 6 (2d6) if Algorath is under half health and 9 (3d6) if he has dropped to 0 hp or been killed this combat.

Savage Critical: Algorath scores a critical hit on a 19 or a 20 and whenever he scores a critical hit, he deals an additional 25 (5d10) damage on top of the regular crit damage.

Legendary Resistance (7/Day): If Algorath fails a saving throw, he can choose to succeed instead.

Searing Magic: Algorath spells ignores resistance to damage types and treat immunity to damage types as resistance.

Multiple Heads: Algorath can take one re-action per turn, rather than only one per round.

Three Minds:  Algorath can concentrate on up to three spells at once.

Magic Attacks: Algorath's attacks are magical in terms of overcoming resistances.

Colossal Siege Monster: Algorath deals quadruple damage to objects and structures.

Immortal Body: Algorath does not need to eat, drink, breath, or sleep

Multi-attack: Algorath can use his Frightful Presence. He then makes six attacks: three with his bite, two with his claws and one with either his tail or his soul read

Bite: Melee Weapon Attack: +19 to hit, reach 25 ft., one target. Hit: 63 (6d10 + 30) piercing damage. If the target is a large or smaller creature, it is restrained. A target restrained this way has three-quarters cover from attacks outside of Algorath's mouth. On its turn a restrained target can make an opposed strength check to escape, the target can also escapes if Algorath takes 450 or more damage in a single round of combat.

If a creature drops to 0 hp, Algorath can use a bonus action to swallow the creature, instantly killing it. A creature killed this way cannot be revived except by a wish spell. While one or more creatures are restrained in this way Algorath cannot use his multi breath attack.

Claw: Melee Weapon Attack: +19 to hit, reach 15 ft., one target. Hit: 42 (5d10 + 15) slashing damage.

Tail: Melee Weapon Attack: +19 to hit, reach 85 ft., one target. Hit: 57 (6d10 + 25) bludgeoning damage. A large or smaller creature hit by this attack must make a DC 30 strength saving throw or be knocked prone.

Frightful Presence: Each creature of Algorath's choice that is within 340ft. of Algorath and aware of him must succeed on a DC 27 Wisdom saving throw or become frightened of him for 1 minute. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. If a creature's saving throw is successful or the effect ends for it, the creature is immune to Algorath's Frightful Presence for the next 6 hours.

Soul Read: Algorath's examines the soul of a creature that is within 340ft. of him, the creature must make a DC 27 CON saving throw or take 44 (8d10) psychic damage and be paralyzed on a failed save, or half as much damage and not paralyzed on a successful one. The creature can repeat the saving throw at the end of each of its turns, Taking 22 (4d10) Psychic damage on a failed save, or no damage and ending the effect on itself on a success. Algorath learns everything the creature knows, including all of its memories, even if the creature does not remember them.

Divine Wrath (1/Day): Algorath summons 17 (2d10 + 7) radiant spears above him. Algorath makes a ranged weapon attack with each spear: +19 to hit, reach 460 ft. Hit: 21 (2d10 + 10) radiant damage each. A creature hit by a spear is restrained until the end of Algorath's next turn.

If a creature has an evil alignment, it takes an additional 5 damage per spear, it also takes an additional 5 if it has a chaotic alignment (+10 damage if chaotic evil).

Hell's Fury (1/Day): Algorath opens 5 (1d4 + 3) portals above him. Each portal fires 3 (1d4 + 1) bolts of necrotic energy before closing. Algorath makes a ranged weapon attack with each bolt: +19 to hit, reach 460 ft. Hit: 26 (2d10 + 15) necrotic damage. Each creature that is hit cannot regain hit points for 1 round for each bolt that hit them.

If a creature has a good alignment, it takes an additional 5 damage per bolt, it also takes an additional 5 if it has a lawful alignment (+10 damage if lawful good).

Solar Cannon (1/Day): Algorath chooses one point within 5 miles of him that he can see. A 7.5 mile high, 500 ft radius cylindrical beam of sunlight appears centered on the chosen point. All creatures other than Algorath inside the beam must make a DC 30 dexterity saving throw, taking 210 (20d10 + 100) radiant damage and 160 (20d10 + 50) fire damage on a failed save, or half as much damage on a successful save. All creatures inside the beam or looking at it, other than Algorath, are blinded for 3 (1d4 + 1) rounds. The beam deals damage to objects in the area, and ignites flammable objects that aren't being worn or carried.

• Alternate version: Black Sun: Instead of radiant and fire damage, deals necrotic and cold damage respectively. Instead of igniting flammable objects, the area becomes difficult terrain as the ground freezes over.

Judges reckoning (1/day): Algorath lunges 200ft. into the air (this does not use his movement). Algorath gains +5 damage to all attacks until the end of combat. Algorath uses the first effect as part of this action, and the other two as his next two actions.

• Action One (same action as used to activate Judges Reckoning):  Vines grow from the ground and grab at each creature of Algorath's choice within 600ft. of him. Each target must make a DC 27 dexterity saving throw, taking 21 (2d10 + 10) piercing damage and being restrained on a failed save, or half as much damage and not restrained on a successful save. On its turn, a restrained creature can use its action to make a DC 27 strength check to free itself of the vines. Thorns grow within 10ft of where each vine grew, causing the area becomes difficult terrain. When a creature moves into or within the area, it takes 11 (2d6 + 4) piercing damage for every 5ft it travels. The vines are flammable.
• Action Two: 11 (2d6 + 4) bolts of lightning strike the ground within 600ft. of Algorath, each creature that is within 5ft. of a where a bolt strikes must make a DC 27 dexterity saving throw, taking 32 (3d10 +15) thunder damage on a failed save, or half as much damage on a successful save. A creature that fails the save, is stunned and defend for one round. A creature can be struck by more than one lightning bolt.
• Action Three: 13 (3d6 + 3) meteors burst through the clouds slamming into the ground within 600ft. of Algorath. Each creature within a 30ft sphere of where a meteor hits must make a DC 27 dexterity saving throw. A creature takes 22 (4d10) bludgeoning damage and 22 (4d10) fire damage on a failed save, or half as much damage on a successful save. The meteors damages objects in the area and ignite flammable objects that aren't being worn or carried (including the vines summoned in round one).

If the summoned thorns are set on fire, they burn for 5 rounds, dealing an additional 5 (2d4 + 1) fire damage. After that they are burnt to a crisp and destroyed.

Breath Weapons (Recharge 5–6): Algorath uses one of the following breath weapons.

Breath: Algorath exhales a blast of necrotic or radiant energy in a 360-foot cone. Each creature in that area must make a DC 27 Dexterity saving throw, taking 220 (40d10) necrotic or radiant damage on a failed save, or half as much damage on a successful one. A creature that fails the savings throw is blinded for 1 round if the damage was radiant and cannot regain hit points for 3 (1d4 + 1) rounds if the damage was necrotic.

Multi Breath: Algorath exhales a blast of necrotic or radiant energy in three 125-foot cones. Each creature in each area must make a DC 27 Dexterity saving throw, taking 132 (24d10) necrotic or radiant damage on a failed save, or half as much damage on a successful one. A creature that is hit by more than one cone makes the saving throw with disadvantage A creature that fails the savings throw is blinded for 1 round if the damage was radiant and cannot regain hit points for 3 (1d4 + 1) rounds if the damage was necrotic.

Acid Breath: Algorath exhales acid in three 245 ft lines that are 10 ft wide. Each creature in that line must make a DC 22 Dexterity saving throw, taking 83 (15d10) acid damage on a failed save and being covered with acid for 5 (1d6 + 2) rounds, or half as much damage on a successful save and being covered in acid for 2 (1d4) rounds. A creature covered in acid takes 27 (5d10) acid damage at the start of its turn. A creature can spend an action to remove the acid from itself, ending the effect. If a creature wearing armor fails the save and is covered in acid for the full duration, the armor gains a permanent -3 penalty to AC.

Poison Breath: Algorath exhales poisonous gas in a 360-foot cone. Each creature in that area must make a DC 24 Constitution saving throw, taking 98 (16d10) poison damage on a failed save and poisoned for 5 (1d6 + 2) rounds, or half as much damage on a successful one and not poisoned. A creature poisoned by this effect takes 33 (6d10) poison damage at the start of its turn and can't regain hit points, a creature can repeat the saving throw at the end of its turn, ending the effect on itself on a success.

Camouflage: Algorath changes the color of his scales to match his surroundings, making himself almost invisible, a creature must make a successful DC 26 wisdom (perception) check to see him while he is not moving. Creatures have disadvantage on the check if Algorath is in dim light or darkness. Algorath has advantage on dexterity stealth checks as long as he remains in a similar environment to the one he camouflage himself in. This effect ends if Algorath moves to surroundings that are noticeably different from the one in which he camouflaged himself, he ends the effect as a bonus action, a creature casts a spell that creates light on him, or he dies.

Change Shape: Algorath magically polymorphs into a humanoid or beast that has a challenge rating no higher than his own, or back into his true form. He reverts to his true form if he dies. Any equipment he is wearing or carrying is absorbed or borne by the new form (Algorath's choice).

In a new form, Algorath retains his alignment, hit points, Hit Dice, ability to speak, proficiencies, Legendary Resistance, lair actions, and Intelligence, Wisdom, and Charisma scores, as well as this action. His statistics and capabilities are otherwise replaced by those of the new form, except any class features or legendary actions of that form.

Judges Wrath (3/day): Algorath takes three actions this turn. If Algorath is under half health he gains +5 damage to all attacks this turn, this bonus increases to +10 if he has dropped to 0 hp or been killed this combat.

Life Steal (5/Day): Algorath chooses one target within 240 ft of him that is below its hp maximum. The creature must make a DC 27 constitution saving throw, taking 40 necrotic damage on a failed save, or half damage on a successful save, Algorath regains hp equal to twice the damage dealt. If Algorath has dropped to 0 hp or been killed this combat, he instead gains life equal to three times the damage dealt.

Opportunity Spell: When a creature attempts to move out of Algorath's reach he can cast a spell of 5th level or lower targeting the creature. Algorath may spend 1 legendary action to cast a spell of 6th level instead. The spell cast must only target that creature.

Wing Guard:  When a creature makes an attack against Algorath, he can impose one of his wings in between him and the attacker, giving him +3 AC against that attack and reducing the damage by 16 (2d10 + 5) if the attack lands.

Mind Read: When a creature makes an attack against Algorath, he can examines them and learn their patterns, giving the creature disadvantage on attack rolls against Algorath until the end of its next turn and giving Algorath advantage on attack rolls against that creature until the end of his next turn.

Algorath can take 7 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. Algorath regains spent legendary actions at the start of its turn.

Detect: Algorath makes a Wisdom (Perception) check.

Tail Attack: Algorath makes a tail attack.

Claw Attack: Algorath makes a claw attack.

Radiant Spear: Algorath makes a ranged weapon attack :+19 to hit, reach 360 ft. Hit: 20 (2d10 + 10) radiant damage. A creature hit by the spear is restrained until the end of the creatures next turn.

Necrotic Blast: A portal opens up and a blast of necrotic energy fire out before it closes. Algorath makes a ranged weapon attack: +19 to hit, reach 360 ft. Hit: 25 (2d10 + 15) necrotic damage. A creature hit by the blast cannot regain hit points for one round.

Wing Attack (Costs 2 Actions). Algorath beats his wings. Each creature within 75 feet of Algorath must succeed on a DC 25 Dexterity saving throw or take 44 (4d10 + 20) bludgeoning damage and be knocked prone. Algorath can then fly up to half its flying speed.

Lesser Magic:  Algorath casts a spell of 5th level or lower.

Middling Magic (Costs 3 actions):  Algorath casts a spell of 6th level or lower.

Greater Magic (Costs 5 actions):  Algorath casts a spell of 7th level or lower

Hardened Scales: When Algorath drops below half hp he regenerates an additional 5 hp (10 hp if in his lair) at the start of his turn as long as he has at least 1 hit point. His AC also increases to 28. This effect does not end until the end of combat, even if Algorath goes above half hp.

Frenzy: When Algorath drops below half hp he gains + 5 damage to all attacks and his breath weapon recharges on a 4-6. All attack rolls and saving throw DCs increase by 1. When Algorath drops below 1/4 hp the bonuses increase to +10 damage, breath weapon recharges on a 3-6 and all attack rolls and saving throw DCs increase by +2. These bonuses do not end until the end of combat, even if Algorath goes above half or 1/4 hp. If Algorath drops to 0 hp or is killed and gets back up (triggered by the relentless ability), the bonuses increase to +15 damage, breath weapon recharges on a 2-6 and all attack rolls and saving throw DCs increase by +3.

Relentless: The first time Algorath would drop to 0 hp or be killed each combat, he instead gets back up with 950 (50d20 + 450) hp and takes a turn immediately ignoring turn order, normal turn order resumes after Algorath's extra turn. All missing limbs and heads are restored. If Algorath's Divine Judgment or Hells Fury have been used, they recharge. He also regains one use of Judges Wrath and Life Steal.

The second time Algorath would drop to 0 hp or be killed each combat, he instead gets back up with 750 (40d20 + 350) hp and takes a turn immediately ignoring turn order. All missing limbs and heads are restored.

The third time Algorath would drop to 0 hp or be killed each combat, he instead gets back up with 550 (30d20 + 250) hp and takes a turn immediately ignoring turn order. All missing limbs and heads are restored.

Undying: For each additional time Algorath would drop to 0 hp or be killed each combat, he makes a DC 5 constitution savings throw to get back up with 350 hp.. All missing limbs and heads are restored. Each time this feature is used the DC increases by 5. If a 20 is rolled on the d20, Algorath automatically gets back up with 450 hp regardless of the DC.