Chain Master

Devil's Sight. Magical darkness doesn't impede the half-devil's darkvision.

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

Multiattack. The half-devil makes two attacks with its chains.

Chains. Melee Weapon Attack: +8 to hit, reach 10 ft., one target. Hit: 11 (2d6 + 4) fire damage. The target is grappled (escape DC 14) if the half-devil isn't already grappling a creature. Until this grapple ends, the target is restrained and takes 7 (2d6) fire damage at the start of each of its turns.

Hellish Irons (Recharges after a Short or Long Rest). Up to four objects made of iron  and no lager than 1 cubic foot, the half-devil can see within 60 feet of it magically heat up and animate under the half-devil's control, provided that the objects aren't being worn or carried. The irons may take the form of a swarm such as a cloud of nails but attacks and reacts as a single creature. The animated irons may also make attacks, including grappling on spiritual weapons.

Each animated iron is an object with AC 20, 20 hit points, resistance to piercing damage, and immunity to psychic and thunder damage. When the half-devil uses multiattack on its turn, it can use each animated iron to make one additional iron attack. An animated iron can grapple one creature of its own but can't make attacks while grappling. An animated iron reverts to its inanimate state if reduced to 0 hit points or if the devil is incapacitated or dies.

Unnerving Mask. When a creature the half-devil can see starts its turn within 30 feet of the devil, the half-devil can create the illusion that it looks like one of the creature's departed loved ones or bitter enemies. If the creature can see thehalf-devil, it must succeed on a DC 14 Wisdom saving throw or be frightened until the end of its turn.