Summon Fiend

Demonic Fiendish Spirit

Large Fiend, Unaligned

Armor Class 12 + spell level (natural armor)
Hit Points 70 + 10 per upcast
Speed 40 ft., fly 70 ft.

Damage Resistances acid, cold, lightning
Damage Immunities fire, poison
Condition Immunities Poisoned
Senses darkvision 120 ft., passive Perception 13
Languages Abyssal, Infernal, telepathy 120 ft.

Traits

Fire Aura. At the start of each of the fiend's turns, each creature within 5 feet of it takes 1d10 fire damage, and flammable objects in the aura that aren't being worn or carried ignite. A creature that touches the fiend or hits it with a melee attack while within 5 feet of it takes 1d10 fire damage.

Death Throes. 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 DC Caster Spell Save DC Dexterity saving throw. A creature takes 2d10 + 6 fire damage on a failed save, or half as much damage on a successful one.

Magic Resistance. The fiend has Advantage on saving throws against spells and other magical effects.

Actions

Multiattack. The fiend makes a number of attacks equal to one third of this spell's level (rounded up).

Longsword. Melee Weapon Attack: +Spell Attack modifier to hit, reach 5 ft., one target. Hit: 1d8 + 3 + Spell Level slashing damage plus 1d4 lightning damage. If the fiend scores a critical hit, it rolls damage dice three times, instead of twice.

Devilish Fiendish Spirit

Large Fiend, Unaligned

Armor Class 12 + spell level (natural armor)
Hit Points 70 + 10 per upcast
Speed 40 ft., fly 70 ft.

Damage Resistances acid, cold, lightning
Damage Immunities fire, poison
Condition Immunities Poisoned
Senses darkvision 120 ft., passive Perception 13
Languages Abyssal, Infernal, telepathy 120 ft.

Traits

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

Fear Aura. Creatures of the fiend's choice that start their turn within 20 feet of it must make a DC Caster Spell Save DC Wisdom saving throw. On a failed save, the creature is Frightened until the start of its next turn. if the creature's saving throw is successful, the creature is immune to the fiend's Fear Aura for the next 24 hours.

Innate Spellcasting. The fiend uses your spellcasting ability modifier and spell save DC. It can innately cast the following spells, requiring no material components:
At will: detect magic

Magic Resistance. The fiend has Advantage on saving throws against spells and other magical effects.

Actions

Multiattack. The fiend makes a number of attacks equal to one third of this spell's level (rounded up).

Hurl Hellfire. Ranged Spell Attack: +Spell Attack modifier to hit, range 150 ft., one target. Hit: 2d6 + 3 + Spell Level fire damage. On a critical hit, the creature begins Burning for 2d6 fire damage. This Burning does not provoke a saving throw at the end of each turn. If the target is a flammable object that isn't being worn or carried, it begins Burning.

Hurl Hellfrost. Ranged Spell Attack: +Spell Attack modifier to hit, range 150 ft., one target. Hit: 2d6 + 3 + Spell Level cold damage. On a critical hit, if the target is a creature, it begins Freezing immediately. If the target is a liquid that can freeze, it freezes in a 10-foot cube for 1 hour.

Yugoloth Fiendish Spirit

Large Fiend, Unaligned

Armor Class 12 + spell level (natural armor)
Hit Points 70 + 10 per upcast
Speed 40 ft., fly 70 ft.

Skills Arcana +5 + PB, Deception +3 + PB, Insight +3 + PB, Perception +3 + PB
Damage Resistances cold, fire, lightning
Damage Immunities acid, poison
Condition Immunities Poisoned
Senses darkvision 120 ft., passive Perception 13 + PB
Languages Abyssal, Infernal, telepathy 120 ft.

Traits

Innate Spellcasting. The fiend uses your spellcasting ability modifier and spell save DC. It can innately cast the following spells, requiring no material components:
At will: alter self, darkness, detect magic, invisibility (self only), mage hand, minor illusion

Magic Resistance. The fiend has Advantage on saving throws against spells and other magical effects.

Actions

Multiattack. The fiend makes a number of attacks equal to one third of this spell's level (rounded up).

Claws. Melee Weapon Attack: +Spell Attack modifier to hit, reach 5 ft., one target. Hit: 1d8 + 3 + Spell Level slashing damage plus 1d4 poison damage. If the fiend scores a critical hit, the target is Poisoned for 1 minute.

Bonus Actions

Teleport. The fiend magically teleports, along with any equipment it is wearing or carrying, up to 60 feet to an unoccupied space it can see.

Rakshasa Fiendish Spirit

Large Fiend, Unaligned

Armor Class 12 + spell level (natural armor)
Hit Points 70 + 10 per upcast
Speed 40 ft., fly 70 ft.

Skills Deception +5 + PB, Insight +3 + PB, Perception +3 + PB
Damage Vulnerabilities piercing
Damage Resistances damage from spells; bludgeoning, slashing
Damage Immunities poison
Condition Immunities Poisoned
Senses darkvision 120 ft., passive Perception 13 + PB
Languages Abyssal, Infernal, telepathy 120 ft.

Traits

Innate Spellcasting. The fiend uses your spellcasting ability modifier and spell save DC. It can innately cast the following spells, requiring no material components:
At will: detect thoughts, disguise self, detect magic, mage hand, minor illusion

Magic Resistance. The fiend has Advantage on saving throws against spells and other magical effects.

Actions

Multiattack. The fiend makes a number of attacks equal to one third of this spell's level (rounded up).

Claws. Melee Weapon Attack: +Spell Attack modifier to hit, reach 5 ft., one target. Hit: 1d8 + 3 + Spell Level slashing damage plus 1d4 psychic damage. If the fiend scores a critical hit, the target is Charmed for 1 minute. Whenever the fiend damages the target, it can make a DC Caster Spell Save DC Wisdom saving throw, ending the effect on a success.

Bonus Actions

Invisibility. The fiend magically turns Invisible until it takes a hostile action.