Legendary Resistance (3/Day). If Adonides fails a saving throw, he can choose to succeed instead.

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

Magic Weapons. Adonides's weapon attacks are magical.​

Regeneration. Adonides regains 10 hit points at the start of his turn. If he takes radiant damage, this trait doesn’t function at the start of his next turn. Adonides dies only if he starts his turn with 0 hit points and doesn’t regenerate.

Innate Spellcasting. Adonides' spellcasting ability is Charisma (spell save DC 22). Adonides can innately cast the following spells, requiring no material components:

At will: animate dead, cone of cold, detect magic, ice storm,  pyrotechnics (4d8 damage), wall of ice

3/day each: dispel magic, lightning bolt (5th level spell slot for 10d6 lightning damage)

 1/day each: heal (self or by touch only), ice storm (8th level spell slot for 6d8 bludgeoning damage plus 4d6 cold damage),  symbol (of stunning)

Sinful Insight. If a creature starts its turn within 30 feet of Adonides and the two of them can see each other, Adonides can force the creature to make a DC 22 Charisma saving throw if Adonides isn't incapacitated. On a failed save, Adonides's supernatural gaze pierces the target's soul, and the devil can see what the creature's alignment is (i.e. chaotic good) and automatically knows whenever the creature lies in any conversation Adonides can follow. This effect lasts for 10 minutes or until the target goes outside the 30 ft. range and can be countered by any effect that would work against a 2nd-level divination spell. A target that successfully saves is immune to Adonides's Sinful Insight for the next 24 hours.​

Multiattack. Adonides can use his Finger of Terror and makes three attacks with his twisted spiked staff.

Twisted Staff. Melee Weapon Attack: +14 to hit, reach 10 ft., one target. Hit: 14 (2d6 + 7) force damage plus 9 (2d8) cold damage.

Finger of Terror. Adonides points his index finger at a creature he can see within 60 feet. The target must succeed on a DC 22 Wisdom save or become frightened for one minute. The target can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.​

Teleport. Adonides teleports, along with any equipment he is wearing or carrying, up to 120 feet to an unoccupied space he can see.

Devilish Mockery. Adonides speaks to a target within 60 feet. If the target can hear Adonides, it must succeed on a DC 22 Wisdom saving throw or take 21 (6d6) psychic damage and have disadvantage on the next attack roll it makes before the end of its next turn.​

Fiendish Invective (Costs 2 Actions). Adonides uses Devilish Mockery.

Hellfire Blizzard (Costs 2 Actions). Adonides hurls a gout of infernal energy to a point within 150 feet which explodes. Each creature in a 20-foot-radius sphere centered on that point must make a DC 22 Dexterity saving throw. The explosion causes 5 (1d10) bludgeoning, cold, fire or lightning damage plus 5 (1d10) bludgeoning, cold, fire or lightning damage on a failed save, or half as much damage on a successful one. Adonides chooses two damage types for the Hellfire Blizzard when he hurls it (i.e. 1d10 cold plus 1d10 lightning), but may not choose the same type twice (i.e. it cannot be 2d10 bludgeoning).​​

Infernal Hopscotch. Adonides magically teleports himself or an ice devil, along with any equipment they are wearing or carrying, up to 120 feet to an unoccupied space he can see. The ice devil must be within 120 feet and in telepathic communication with Adonides. Only the destination point must be visible: Adonides can teleport an ice devil from somewhere he cannot see.