Baalzebul

Magic Weapons. Baalzebul's weapon attacks are magical.

Legendary Resistance (3/Day). If Baalzebul fails a saving throw, he can choose to succeed instead.

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

Regeneration. Baalzebul regains 20 hit points at the start of his turn. If he takes radiant damage, this trait doesn’t function at the start of his next turn. Baalzebul dies only if he starts his turn with 0 hit points and doesn’t regenerate.

Innate Spellcasting. Baalzebul's innate spellcasting ability is Wisdom (spell save DC 22 +14 to hit). Baalzebul can innately cast the following spells, requiring no material components:

At will: Animate dead, Blasphemous flame*, Blight, Charm monster, Create undead (8th level), Detect good and evil (good only), Detect magic, Fireball, Geas, Hold monster, Impish agitator*, Insect plague, Scrying, Suggestion

3/day each: Greater restoration, Major image, Resurrections, Wall of eyes**

1/day each: Aspect of the pit fiend*, Symbol (Pain or insanity only), Wish
* Means the spell is within Hellish depths pdf. 
** Means the spell is within Billy's guide to everything pdf. 

Multi attack. Baalzebul makes two slam attacks and uses their horrid gaze attack. 

Slam. Melee Weapon Attack: +18 to hit, reach 5 ft., 1 target. Hit: 32 (4d10 + 10) bludgeoning damage and the target must make a DC 26 Strength saving throw or have their speed reduced to 0 or have a -10 penalty to all damage (Baalzebul's choice). These effects last until the end of Baalzebul's next turn. 

Horrid Gaze. Baalzebul's eyes rest upon one creature who he can see within 50ft of himself causing them to make a DC 22 Wisdom saving throw or be frightened of Baalzebul for 1 minute. The target also must make a second DC 22 Wisdom saving throw or have disadvantage on all Strength based skill checks, attack rolls and saving throws. Creatures can remake failed save(s) at the end of their next turn. 

Insect gorge (Recharges on 6). Baalzebul disgorges a massive cloud of biting flies which spread forth into a 60ft cone which remains in effect until the start of Baalzebul's next turn. Any creature in the cone of the cloud for either the first time on their turn or starting their turn there must make a DC 26 Constitution saving throw or take 70 (20d6) acid damage, half as much on a successful saving throw. 

Teleport. Baalzebul magically teleports, along with any equipment he is wearing and carrying, up to 120 feet to an unoccupied space he can see.

Summon Devil (2/Day). Baalzebul chooses what to summon and attempts a magical summoning.

Baalzebul has a 100 perCacent chance of summoning 1d10 horned devils, 1d4 +1 Ice devils or 1d3 pit fiends. 

A summoned devil appears in an unoccupied space within 60 feet of Baalzebul, acts as an ally of Baalzebul, and can’t summon other devils. It remains for 1 minute, until it or Baalzebul dies, or until Baalzebul dismisses it as an action.

Baalzebul can take 3 legendary actions, choosing from the options below. Only one legendary action can be used at a time and only at the end of another creature's turn. Baalzebul regains spent legendary actions at the start of his turn.

Cast a spell (Costs 1 Action). Baalzebul casts a spell from their innate spellcasting. 

Teleport (Costs 1 Action). Baalzebul uses his Teleport action. 

Aura of flies (Costs 3 Actions). Until the start of Baalzebul's next turn he counts as having three quarter cover. Each creature that starts their turn or enters within 20ft of Baalzebul takes 35 (10d6) acid damage. Whilst this ability is active Baalzebul can't use their Insect gorge action.