Captain Gurren, Herald of Death

Legendary Resistance (3/Day). If Gurren fails a saving throw, he can choose to succeed instead.

Radiant Judgement. Once per day, Captain Gurren's wings unfurl, shining with golden light, allowing him to fly for up to 1 hour. During this time, his hammer attacks deal an additional 20 (4d10) radiant damage, and he emits a 30-foot aura of divine retribution. Enemies within the aura that attack Gurren take 25 (5d10) radiant damage, and allies benefit from advantage on saving throws against necrotic and poison damage.

Hammer of the Void (Fellstar). Captain Gurren wields Fellstar, a massive cursed warhammer. This enchanted weapon deals 3d12+8 bludgeoning damage on a hit. Additionally, the target must succeed on a DC 21 Constitution saving throw or be stunned until the end of its next turn. Gurren can channel necrotic energy through Fellstar, regaining hit points equal to half the damage dealt. When used during Radiant Judgement, Fellstar instead heals Gurren for the full damage dealt.

Aura of Final Reckoning. Captain Gurren constantly emanates a 15-foot aura of doom. At the start of each enemy's turn within the aura, they must succeed on a DC 20 Charisma saving throw or suffer 30 (6d10) necrotic damage and become frightened until the end of their next turn. Creatures who succeed on this saving throw are immune to the aura's effects for the next 24 hours.

Cleric of Death. Captain Gurren can cast spells as a 20th-level cleric. His spellcasting ability is Wisdom (spell save DC 23, +15 to hit with spell attacks). He has the following spells prepared:

At will: thaumaturgy, detect magic, spare the dying

3/day each: spirit guardians, shield of faith, cure wounds

1/day each: divine word, banishment, mass heal

Multiattack. Captain Gurren makes three attacks with Fellstar.

Fellstar Strike. Melee Weapon Attack: +16 to hit, reach 10 ft., one target. Hit: 31 (3d12 + 8) bludgeoning damage plus 22 (4d10) necrotic damage. The target must succeed on a DC 21 Constitution saving throw or be stunned until the end of its next turn.

Hammer of Souls. Ranged Spell Attack: +15 to hit, range 60 ft., one target. Hit: 45 (8d8+7) radiant damage. A creature reduced to 0 hit points by this attack must make a DC 20 Wisdom saving throw or have its soul torn from its body and absorbed into Fellstar. Gurren heals for 40 hit points each time a creature's soul is absorbed.

Hellrider's Charge (Recharge 6). Captain Gurren charges in a straight line up to 50 feet. Each creature in his path must succeed on a DC 21 Dexterity saving throw or be knocked prone and take 44 (10d6) bludgeoning damage. He can make one Fellstar Strike as part of this action.

Breath of Retribution (Recharge 5-6). As a black dragonborn, Captain Gurren can unleash an acidic breath in a 60-foot long and 5 foot wide line. All creatures in the area must make a DC 21 Dexterity saving throw, taking 72 (16d8) acid damage on a failed save, or half as much damage on a successful one. Any creature reduced to 0 hit points by this attack is enveloped in dark energy, creating a shadowy duplicate of the creature under Gurren's control for 1 minute.

Captain Gurren 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. Gurren regains spent legendary actions at the start of his turn.

Divine Rebuke. Captain Gurren can make a single Fellstar Strike against any creature that attacks him.

Fellstar's Wrath (Costs 2 Actions). Gurren slams Fellstar into the ground, releasing a shockwave of necrotic energy. All enemies within 30 feet must make a DC 22 Constitution saving throw, taking 55 (10d10) necrotic damage on a failed save, or half as much on a successful one.

Invoke the Helldivers (Costs 3 Actions). Gurren calls upon the specters of his fallen comrades, summoning 3 Helldivers to fight by his side. Each Helldiver has the following statistics: AC 20, Hit Points: 100, Speed: 30 ft, and can make two melee attacks with enchanted glaives (Hit: +8 to hit, damage: 2d10+4 slashing).