Baal, Lord of Destruction

Devil’s Sight. Magical darkness does not impede Baal’s darkvision.

Great Evil. If Baal is killed then his spirit returns to the Black Abyss, where his body will reform after 1d100 years.

Legendary Resistance (3/Day, or 5/Day in Lair). If Baal fails a saving throw, he can choose to succeed instead.

Lord of Destruction. Baal’s destructive touch corrupts and shatters all things. When Baal hits an object or structure with an attack, it takes double damage.

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

Rampage. If Baal reduces a creature to 0 hit points on his turn, he can immediately move up to half his speed and make one additional attack against a different creature without using an action.

Multiattack. Baal makes two Tentacle attacks and one Mote of Ruin attack.

Tentacle. Melee Weapon Attack: +16 to hit, reach 10 ft., one target. Hit: 17 (2d8 + 8) piercing damage and 9 (2d8) necrotic damage. If the target is a creature, it must succeed on a DC 24 Constitution saving throw or its hit point maximum is reduced by an amount equal to the damage taken. This reduction lasts until the target finishes a long rest or a Greater Restoration spell is cast on them. The target dies if its hit point maximum is reduced to 0.

Mote of Ruin. Ranged Spell Attack: +16 to hit, range 120 ft., two targets. Hit: 36 (8d8) force damage. If a creature is reduced to zero hit points by this attack, its body bursts into bits.

Quaking Blast (Recharge 5–6). An explosive force bursts forth from Baal and is sent out in every direction. Each creature other than Baal in a 60-ft radius sphere around him must make a DC 24 Dexterity saving throw, taking 35 (10d6) fire damage and 35 (10d6) bludgeoning damage on a failed save, or half as much damage on a successful one. This ability also causes the affected area to become difficult terrain. Baal is not affected by the difficult terrain caused by this ability.

Spellcasting. Baal casts one of the following spells, requiring no material components and using Intelligence as the spellcasting ability (spell save DC 24, +16 to hit with spell attacks).

At will: Gravity Sinkhole, Hellish Rebuke, Shield, Thunder Step

3/day each:  Destructive Wave, Disintegrate, Gravity Fissure, Mordenkainen's Sword

1/day each: Dark Star, Ravenous Void

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

Legendary Action Uses: 3 (4 in Lair). Immediately after another creature’s turn, Baal can expend a use to take one of the following actions. Baal regains all expended uses at the start of each of his turns.

Destructive Magic. Baal uses Spellcasting or Teleport.

Festering Appendage. Baal summons festering appendages next to a creature he can see within 60 feet. He then makes one Tentacle attack against that creature. Hit or miss, the appendages then vanish.

Lord of Hell (Costs 2 Actions). Baal magically summons a vlazok. The vlazok appears in an unoccupied space within 60 feet of Baal, acts as Baal’s ally, and acts on its own initiative. The vlazok remains until Baal dies or he dismisses it as an action.