Cursed Oriendar

Shapechanger. The Demon can use its action to polymorph into a Medium or large humanoid it has seen, or back into its true form. Its statistics, other than its size, are the same in each form. Any equipment it is wearing or carrying isn't transformed. It reverts to its true form if it dies.

Barbed Hide. At the start of each of its turns, the devil deals 1d10+6(Con mod) piercing damage to any creature grappling it.

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

Innate Spellcasting. Orieendar's spellcasting ability is Charisma (spell save DC 20). Orieendar can innately cast the following spells, requiring no material components:

At will: fireball

3/day each: hold monster, hold person, firewall

Multiattack. The devil makes four melee attacks: one with its tail, one with its bite and two with its claws. Alternatively, He can cast an innate magical ability.

Claw. Melee Weapon Attack: +13 to hit, reach 10 ft., one target. 2d8+7 slashing damage.

Bite. Melee Weapon Attack: +13 to hit , reach 5 ft., one target. 4d6+7 piercing damage.

Tail. Melee Weapon Attack: +13 to hit, reach 10 ft., one target. 3d10+7 piercing damage.