Warden

Fire Absorption. Whenever the Warden is subjected to fire damage, it takes no damage and instead regains a number of hit points equal to the fire damage dealt.

Immutable Form. The Warden is immune to any spell or effect that would alter its form.

Magic Resistance. The Warden has advantage on saving throws against spells and other magical effects.

Soul Absorption. If the Warden deals fatal damage to a creature, it regains 6d10 hit points.

Multiattack. The Warden makes two slam attacks.

Slam. Melee Weapon Attack: +15 to hit, reach 5 ft., one target. Hit: 24 (4d8 + 8) bludgeoning damage.

Poison Breath (Recharge 4-6). The Warden exhales poisonous gas in a 15-foot cone. Each creature in that area must make a DC 19 Constitution saving throw, taking 45 (10d8) poison damage on a failed save, or half as much damage on a successful one.

Sonic Blast (Recharge 5-6). The targeted creature must succeed on a DC 16 Dexterity saving throw or take 65 (12d10) force damage, become deafened for 3 minutes, and be knocked back 5ft for every 10 damage taken.

The Warden 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. The Warden regains spent legendary actions at the start of its turn.

Attack. The Warden makes one slam attack or one poison breath attack.

Move. The Warden moves up to half its speed.

Harden. The next damage the Warden receives is halved.