Fire Aura. At the start of each of Zirisk's turns, each creature within 10 feet of it takes 7 (2d6) fire damage, and flammable objects in that aura that aren't been worn or carried ignite. A creature that touches Zirisk or hits it with a melee attack while within 5 feet of him takes 7 (2d6) fire damage.

Illumination. Zirisk sheds bright light in a 30-foot radius and dim light for an additional 30 feet.

Regeneration. Zirisk regains 10 hit points at the start of its turn. If Zirisk takes cold damage or is immersed in water, this trait doesn't function at the start of Zirisk's next turn. Zirisk only dies if he starts his turn with 0 hit points and doesn't regenerate.

Spellcasting (Phase 3). Zirisk is an 11th-level spellcaster. Its spellcasting ability is Wisdom (spell save DC 16, +8 to hit with spell attacks), and it needs only verbal components to cast its spells. It has the following cleric spells prepared:

Cantrips (at will): mending, sacred flame, thaumaturgy

1st level (4 slots): command, cure wounds, shield of faith

2nd level (3 slots): calm emotions, hold person

3rd level (3 slots): bestow curse, clairvoyance

4th level (3 slots): banishment, freedom of movement

5th level (2 slots): flame strike, geas

6th level (1 slot): true seeing

Multiattack. Zirisk makes one Bite attack and one Tail attack.

Bite. Melee Weapon Attack: +11 to hit, reach 10 ft., one target. Hit: 12 (1d10 + 7) piercing damage plus 18 (4d8) fire damage.

Tail. Melee Weapon Attack: +11 to hit, reach 10 ft., one target. Hit: 11 (1d8 + 7) bludgeoning damage plus 14 (4d6) fire damage. If the target is a large or smaller creature, it must succeed on a DC 19 strength saving throw or be pushed up to 10 feet away from Zirisk and knocked prone.

Pyroclasm (Recharge 5-6). Gouts of molten lava erupt from Zirisk's body. Each creature within a 30-foot-radius sphere centered around Zirisk's body must make a DC 15 Dexterity saving throw. On a failed saving throw, a creature takes 21 (6d6) fire damage and 21 (6d6) bludgeoning damage. On a successful saving throw, a creature takes half as much damage.

(Phase 2) Zirisk can take 2 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. Zirisk regains spent legendary actions at the start of its turn.

Detect. Zirisk makes a Wisdom (Perception) check.

Tail Swipe. Zirisk makes one tail attack that can't knock a creature back or prone and deals 7 (2d6) fire damage.