Archdevil Arkhan the Cruel

Aura of Hate. While Arkhan isn’t incapacitated, he and all fiends and undead within 30 feet of him deal 9 extra damage whenever they hit with a melee weapon attack (already factored into Arkhan’s attacks). This extra damage is of the same type as the weapon’s damage type.

Hand of Vecna. Arkhan has mastered the Hand of Vecna. Effectively suppressing the will of Vecna. The hand no longer has charges. You can use an action to cast one of the following spells (Spell Save DC 25, +17 to hit with spell attacks):

• 2/day Finger of Death
• 3/day Sleep (7th Level) (roll 17d8)
• 3/day Slow (7th Level)
• 2/day Teleport (with no chance of error)

Innate Spellcasting. Arkhan’s spellcasting ability is Charisma (spell save DC 25, +17 to hit with spell attacks). Arkhan always has death ward cast on him before combat, if he can cast it. He can cast the following spells, requiring no material components:

• At will: Dimension Door, Misty Step
• 3/day each: Animate Dead (7th Level), Contagion, Greater Restoration, Raise Dead
• 1/day each: Create Undead(9th Level), Death Ward, Geas (7th Level)

Devil's Sight. Magical darkness doesn't impede Arkhan's darkvision.

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

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

Magic Weapons. Arkhan's weapon attacks are magical.

Regeneration. Arkhan regains 20 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. Arkhan dies only if he starts his turn with 0 hit points and doesn't regenerate.

Smite of the Archduke (3/day). Arkhan may as part of hitting a creature with a melee weapon attack. He can deal an extra 5d8 necrotic damage to the attack.

Special Equipment. Arkhan wields Fane-Eater and wears a suit of Obsidian Flint Dragon Plate. The armor gives Arkhan advantage on ability checks and saving throws made to avoid or end the grappled condition on him.

Multiattack. Arkhan attacks three times with Fane-Eater. Arkhan can substitute one Fane-Eater attack for a Paralyzing Swipe attack or an Infernal Breath Attack if it is charged.

Fane-Eater (Battleaxe). Melee Weapon Attack: +18 to hit, reach 10 ft., one target. Hit: 21 (2d8 + 17) slashing damage, plus 9 (3d8) cold damage (Hand of Vecna). If the target is a creature and Arkhan rolls a 20 on the attack roll, the creature takes an extra 9 (2d8) necrotic damage, and Arkhan regains an amount of hit points equal to the necrotic damage dealt.

Infernal Breath Attack (Recharge 5–6). Arkhan exhales fire in a 60-foot cone. Each creature in that area must make a DC 25 Dexterity saving throw, taking 32 (12d6) fire damage and 30(7d8) poison damage on a failed save, or half as much damage on a successful one.

Paralyzing Swipe. Melee Spell Attack: +17 to hit, reach 10 ft., one creature. Hit: 32 (6d6) necrotic damage plus 10 (2d8) cold damage. The target must succeed on a DC 25 Constitution saving throw or be  paralyzed for 1 minute. The target can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.

Arkhan can take 3 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. Arkhan regains spent legendary actions at the start of its turn.

Charge. Arkhan can move up to his speed.

Fane-Eater. Arkhan makes a Fane-Eater attack towards an enemy within range.

Infernal Breath Attack (Costs 2 Actions). If charged, Arkhan makes a 60 ft. cone Infernal Breath attack.

Paralyzing Swipe (Costs 2 Actions). Arkhan makes a Paralyzing swipe attack towards an enemy within range.