Trobriand

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

Trobriand is immune to any spell or effect that would alter its form.

Trobriand has advantage on saving throws against spells and other magical effects.

Trobriand's weapon attacks are magical.

Trobriand makes two melee attacks.

Melee Attack Roll: +13 to hit, reach 5 ft., one target. Hit: 20 (3d8 + 7) bludgeoning damage.

Melee Attack Roll: +13 to hit, reach 10 ft., one target. Hit: 23 (3d10 + 7) slashing damage.

Trobriand 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.

Trobriand is an 18th-level spellcaster. His spellcasting ability is Intelligence (spell save DC 20, +12 to hit with spell attacks). He has the following wizard spells prepared:

Cantrips: fire bolt, mage hand, prestidigitation

Level 1 (4 slots): detect magic, magic missile, shield

Level 2 (3 slots): blur, detect thoughts, misty step, shatter

Level 3 (3 slots): counterspell, dispel magic, fireball, haste

Level 4 (3 slots): blight, greater invisibility

Level 5 (3 slots): animate objects, Bigby's hand, scrying

Level 6 (1 slots): chain lightning, globe of invulnerability

Level 7 (1 slots): finger of death, forcecage

Level 8 (1 slots): incendiary cloud, power word stun

Level 9 (1 slots): power word kill