Bishamon

Adamantine Plating. Any critical hit against Bishamon becomes a normal hit.

Action Surge(2/day). Bishamon can take one additional action this turn(no action).

Indomitable(3/day). Bishamon can reroll a saving throw that it fails using the new roll.

Rapid Strike. If Bishamon takes the Attack action on its turn and has advantage on an attack roll against one of the targets, it can forgo the advantage for that roll to make an additional weapon attack against that target, as part of the same action. It can do so no more than once per turn.

Cursed Wounds. If Bishamon scores a critical hit with Blade Strike or Great Blade Strike, the target’s AC is reduced by 3 until the end of their next turn.

Mage Slayer. When Bishamon damages a creature that is concentrating on a spell, that creature has disadvantage on the saving throw it makes to maintain its concentration. 

Slash Tendons. Once per turn, when Bishamon hits a creature with an attack that deals slashing damage, it can reduce the speed of the target by 10 feet until the start of Bishamon’s next turn.

Limited Magic Resistance. Bishamon has advantage on saving throws against spells cast by creatures within 5 feet of it.

Crippling Slash. When Bishamon scores a critical hit that deals slashing damage to a creature, the target has disadvantage on all attack rolls until the start of Bishamon’s next turn.

Mobile Attacks. When Bishamon makes a melee attack against a creature, it doesn’t provoke opportunity attacks from that creature for the rest of the turn, whether the attack hit or not.

Great Weapon Fighting. Once per hit, Bishamon can reroll any dice that rolled a 1 or 2, using the result of the second roll even if it is a 1 or 2.

Constructed Resilience. Bishamon has advantage on saving throws against being poisoned, is immune to disease, doesn’t need to eat, drink, sleep or breathe, and magic can’t put him to sleep.

Multiattack. The Lord of Blades makes four attacks which can be any combination of Blade Strikes, Great Blade Strikes or Lobbed Strikes.

Blade Strike. Melee Weapon Attack: +14 to hit, reach 10 ft., one target. Hit: 15 (2d6 + 8) slashing damage plus 6 (1d10) necrotic damage. Bishamon regains HP equal to the necrotic damage. 

Great Blade Strike. Melee Weapon Attack: +9 to hit, reach 10 ft., one target. Hit: 25 (2d6 + 18) slashing damage plus 6 (1d10) necrotic damage. Bishamon regains HP equal to the necrotic damage. 

Lobbed Strike. Melee or Ranged Weapon Attack: +11 to hit, reach 5 ft. or range 20/60 ft., one target. Hit: 8 (1d6 + 5) slashing damage.

Hex(1/day). Bishamon place a curse on a creature it can see within 60ft. Until the spell ends, Bishamon deals an extra (1d6) necrotic damage to the target whenever it hits them with an attack. The target has disadvantage on ability checks made with a chosen ability.

If the target drops to 0 hit points before this spell ends, Bishamon can use a bonus action on its subsequent turn to curse a new creature.

Misty Step(1/day). Bishamon teleports up to 30 feet to an unoccupied space that it can see.

Fighting Spirit(3/day). Bishamon can give itself advantage on weapon attack rolls until the end of the current turn and it gains 15 temporary HP.

Chromatic Infusion(1/day). Bishamon’s weapon deals an extra (1d4) damage of the chosen type when it hits

Great Weapon Master Attack. When Bishamon scores a critical hit with a melee weapon or reduces a creature to 0 HP, it can make one melee weapon attack as a bonus action.

Second Wind(1/day). Bishamon can use a bonus action to regain (1d10+20) HP.

Reactive Resistance(6/day). When Bishamon takes acid, cold, fire, lightning, or poison damage, it can use its reaction to give itself resistance to that instance of damage.

Mage Slayer Attack. When a creature within 5 ft. of Bishamon casts a spell, it can use its reaction to make a melee weapon attack against that creature.

Strength Before Death(1/day). If Bishamon takes damage that reduces it to 0 HP and doesn’t kill it, Bishamon can use its reaction to delay falling unconscious, and can immediately take an extra turn, interrupting the current one. During that extra turn, taking damage causes death saving throw failures as normal, and three death saving throw failures can still kill it. When the extra turn ends, it only falls unconscious if it still has 0 HP.