Asmodeus

Legendary Resistance (1/Day). If the Asmodeus fails a saving throw, it can choose to succeed instead.

Alluring present. Within 100 ft and aware of Asmodeus, you must succeed a DC 15 Charisma savings throw at the start of your turn to keep concentration on spells  if you fail you lose concentration of the spell

Spellcasting. Asmodeus spellcaster. Its spellcasting ability is Its spellcasting ability is Charisma (spell save DC 18, +10 to hit with spell attacks).

• (at will) dimension door, Phantasmal Force, Phantasmal Killer, Hypnotic Pattern, 
  Mirage Arcane, Suggestion, Otto's Irresistible Dance, Enthrall, Confusion, Command, Dominate Monster, Teleport

   

Multiattack. The Asmodeus can use its Charming Presence. It then makes two attacks: with its claws.

Claw. Melee Weapon Attack: 1d20+12 reach 5 ft., one target. Hit: (2d6 + 7) slashing damage. + (1d10+7) Fire damage 

Charming Presence. Each creature of Asmodeus's choice that is within 120 feet of the Asmodeus and aware of it must succeed on a DC 17 Charisma savings throw or become Charmed for 1 minute. A creature can repeat the saving throw at the end of each turn, 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 Asmodeus's Charming Presence for the next 1 minute

The Asmodeus 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. The Asmodeus regains spent legendary actions at the start of its turn.

Spell casting. (Costs 2 Actions). cast at will spell level five or lower

Claw Attack. (Costs 1 Action). Melee Weapon Attack: 1d20+12 reach 5 ft., one target. Hit: (2d6 + 7) slashing damage. + (1d10+7) Fire damage

Firey passion (Costs 1 Action). Any number of creatures Charmed by Asmodeus takes 2D10+7 fire damage the damage does not end the charmed effect

Charming smoke bomb (Costs 2 Actions) Asmodeus Casts Darkness Any creature within the darkness at the start of their turn has to make a DC 20 Charisma saving throw or be Charmed for one minute ending the effect on itself on a success.