Ashen

Aggressive. As a bonus action, the ashen can move up to its speed toward a hostile creature that it can see.

Fiery Rebirth. When the ashen drops to 0 hit points, it explodes, and each creature within 15 feet of it must make a DC 15 Dexterity saving throw, taking 28 (8d6) fire damage on a failed save, or half as much on a successful one. The explosion ignites flammable objects in that area that aren't being worn or carried. The ashen reappears as an immolator at the beginning of its next turn. Its initiative count doesn't change.

Keen Hearing and Sight. The ashen has advantage on Wisdom (Perception) checks that rely on hearing or sight.

Reckless. At the start of its turn, the ashen can gain advantage on all melee weapon attack rolls it makes during that turn, but attack rolls against it have advantage until the start of its next turn.

Thermal Guts. A creature that hits the ashen with a melee attack that, deals piercing or slashing damage, while within 5 feet of it takes 3 (1d6) fire damage.

Multiattack. The ashen makes three claw attacks.

Claw. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 15 (3d8 + 2) slashing damage.