Acidic Blood When Miska is struck by a Piercing or Slashing Weapon for 10 points of damage or more the attacker must make a Con saving throw (DC24) taking 10d6 poison damage on a fail or half on a success

Three heads Miska has advantge on all Wis (perception) checks and gets two bite attacks on attacks of opportunity

Discorperation. When Miska drops to 0 hit points or dies, his body is destroyed but his essence travels back to Pandemonium, where he was imprisoned where he will be once again trapped and unable to take physical form until the staff summons him again. Unless the final blow is struck with the staff. Limited Magic Immunity unless he wishes to be Miska is uneffected by Spells of the 2nd level or lower and has advantage on saving throws against all spells and magical effects.

Actions

Multi-Attack Six melee attacks two with Scimitar of Disintegration, two with +3 morning star and two Bites

Frightful Presence. Each creature of Miska's choice that is within 120 feet of Miska and aware of him must succeed on a DC 24 Wisdom saving throw or become frightened for 1 minute. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. If a creature's saving throw is successful or the effect ends for it, the creature is immune to Miska's Frightful Presence for the next 24 hours.

Scimitar of Disintegration Melee Weapon Attack: Any lawful creature struck by this scimitar must succeed at a con save (DC 19) or be destroyed as if by a disintegrate spell. Otherwise + 15 to hit, Reach 20 ft, one target. Hit: (1d6+12)

+3 morningstar + 12 to hit, reach 20, one target. Hit: 1d8+10

Bite Melee Weapon attack: +17 to hit, reach 15 ft., one target. Hit: 21 (2d10 + 10) piercing damage plus 4D6 poison, and the target must succeed on a DC 25 Constitution saving throw or be poisoned for the next 5 turns taking an addtional 2d4 damage each turn

Legendary Actions

Miska can take 3 legendary actions per round of combat. Only one legendary action can be use in a turn and only at the end of another creature's turn. Miska regains Legendary action slots at the start of his turn

Summon Demon Miska can automatically summon two Goristro, two balors, two marilith, or two glabrezu. (determined on a D4)

Web Miska shoots webs from his Abdomen. range 30 ft. The webs are non-magical, meaning they can not be dispelled, and are resistanent to fire. Dex save (dc19) to dodge if save is failed the target is restrained and must make a strength check in order to break free.

Howl Miska two wolf heads howl, casting the Dominate Person spell targeting all hostile humaniods within 60 ft. targets must make a wisdom saving throw. If the target fails it is charmed. at the end of each of its turns it can reattempt the wis savind throw, on a success being freed from the spell.