Necrotic Veil (3/Day). When Zyrethrax, the Bound Radiance fails a saving throw, he can succeed instead. When he does, it takes 12 (3d8) of necrotic damage that can't be reduced in any way.

Corrupted radiance. Radiant and necrotic damage dealt by Zyrethrax, the Bound Radiance ignore damage resistance.

Multiattack. Zyrethrax, the Bound Radiance makes one Bite attack and two Claw attacks.

Bite. Melee Weapon Attack: +11 to hit, reach 15 ft., one target. Hit: 16 (2d10+6) piercing damage plus 8 (2d8) necrotic damage, and the target can’t take reactions until the end of their next turn.

Claw. Melee Weapon Attack: +11 to hit, reach 10 ft., one target. Hit: 15 (3d6+6) slashing damage, and Zyrethrax, the Bound Radiance can move the target up to 15 feet horizontally.

Solar Breath (Recharge 5-6): Zyrethrax, the Bound Radiance exhales a beam of light in a 90-foot-long, 5-foot-wide Line. Each creature in that area must make a DC 19 Dexterity saving throw. On a failed save, a creature takes 40 (8d10) radiant damage and has the blinded condition until the end of their next turn. On a successful save, a creature takes half as much damage and suffers no other effect.

Sacred bane. Zyrethrax, the Bound Radiance choose a creature he can see within 60 feet of him and speak celestial words to shut down it's spellcasting ability. The creature make a DC17 Wisdom saving throw. On a failed save, the target takes 9 (3d6) radiant damage and is unable to cast spells until the end of their next turn.

Necrotic chains. When a creature within 5 feet of Zyrethrax, the Bound Radiance hits him with an attack, Zyrethrax, the Bound Radiance releases a burst of necrotic energy. Each creature within 5 feet of him must succeed on a DC 17 Dexterity saving throw. On a failed saved, they're restrained until the end of their next turn. On a successful save, a creature suffers no effect.

Villain Actions

Zyrethrax, the Bound Radiance has three villain actions. He can take each action once during an encounter after an enemy’s turn. He can take these actions in any order but can use only one per round.

Action 1: Blinding wings. Zyrethrax, the Bound Radiance open his wings and take off the ground, illuminating everything around him and hovering 60 feet above the ground, without provoking attacks of opportunity, until the beginning of it's next turn. Every creatures within 120 feet of him must make a DC17 Constitution saving throw. On a failed save, a creature takes 12 (4d6) radiant damage and is blinded until the end of their next turn. On a successful save, a creature takes half as much damage and isn’t blinded.

Action 2: Spectral dome. Zyrethrax, the Bound Radiance invoke 5 Specter, 15 feet away from him, that create a dome of necrotic energy 5 feet around him, pushing every creatures 10 feet away. All five Specter are linked to the dome. Under the dome, Zyrethrax, the Bound Radiance is immune to all damage but can only use his breath weapon if it's recharged at the beginning of it's turn. When the five Specter are down, the dome disappear and Zyrethrax, the Bound Radiance can use all his action, bonus action and reaction again.

Action 3: Solar Bomb. Zyrethrax, the Bound Radiance use the last radiant energy in his body to perform this attack. He fly 60 feet above the ground without provoking attacks of opportunity and start charging a massive radiant sphere in his hands. At the start of it's next turn, he gain altitude, flying 60 more feet above the ground, then he drop the energy directly under him. Any creature in a 100 feet radius sphere must make a DC22 Dexterity saving throw. On a failed saved, they take 60 (15d8) radiant damage and are blinded. On a successful save, a creature takes half as much damage and suffers no other effect. Creatures who have a total covered from the center of the attacks take no damage, but their cover is broken.