Fiendish Spirit

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

When the fiend drops to 0 hit points or the spell ends, the fiend explodes, and each creature within 10 feet of it must make a Dexterity saving throw against your spell save DC. A creature takes 2d10 + summonSpellLevel fire damage on a failed save, or half as much damage on a successful one.

Magical darkness doesn't impede the fiend's darkvision.

The fiend makes a number of attacks equal to half this spell's level (rounded down).

Melee Weapon Attack: your spell attack modifier to hit, reach 5 ft., one target. Hit: 1d12 + 3 + summonSpellLevel necrotic damage.

Melee Weapon Attack: your spell attack modifier to hit, reach 5 ft., one target. Hit: 1d8 + 3 + summonSpellLevel slashing damage. Immediately after the attack hits or misses, the fiend can magically teleport up to 30 feet to an unoccupied space it can see.

Ranged Spell Attack: your spell attack modifier to hit, range 150 ft., one target. Hit: 2d6 + 3 + summonSpellLevel fire damage. If the target is a flammable object that isn't being worn or carried, it also catches fire.