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

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

deal with the devil. Zorgoth forces a creature of its choice to make a (dc 16) wisdom save. on a failed save. the creature gains 1d10 thp as fire bellows around them and infernal chains bind the target to the devil. the creature  is charmed and must obey the devils commands for 1 minute. the creature can repeat the save ending the effects on a success. on a successful save the creature becomes immune to the effect. after zargoth uses this it must recharge it (recharges on a 5 or a 6)

Healing Fire. whenever zargoth takes fire damage. he instead heals for that much

Multiattack. The devil makes three attacks: two with its claws and one with its sting.

Claw. Melee Weapon Attack: +8 to hit, reach 10 ft., one target. Hit: 8 (1d8 + 4) slashing damage.

Sting. Melee Weapon Attack: +8 to hit, reach 10 ft., one target. Hit: 13 (2d8 + 4) piercing damage plus 17 (5d6) poison damage, and the target must succeed on a DC 16 Constitution saving throw or become poisoned 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.