Warlord Oni

Innate Spellcasting: The Warlord Oni's innate spellcasting ability is Charisma (spell save DC 25, +17 to hit with spell attacks). It can innately cast the following spells, requiring no material components:

At will: darkness, fly, sleep, invisibility (self only)

3/day each: chain lightning, fireball, hold monster, plane shift, telekinesis

1/day each: finger of death, power word kill

Legendary Resistance (3/day): If the Warlord Oni fails a saving throw, it can choose to succeed instead.

Magic Weapons: The Warlord Oni's weapon attacks are magical.

Regeneration: The Warlord Oni regains 20 hit points at the start of its turn.

Frightful Presence: Each creature of the Warlord Oni's choice within 120 feet of it and aware of it must succeed on a DC 25 Wisdom saving throw or become frightened for one 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 the Warlord Oni's Frightful Presence for the next 24 hours.

Multiattack: The Warlord Oni makes three attacks: two with its claws and one with its glaive or greatclub.

Claw: Melee Weapon Attack: +18 to hit, reach 15 ft., one target. Hit: 35 (4d12 + 7) slashing damage plus 14 (4d6) fire damage.

Glaive: Melee Weapon Attack: +18 to hit, reach 20 ft., one target. Hit: 45 (6d10 + 10) slashing damage.

Greatclub: Melee Weapon Attack: +18 to hit, reach 15 ft., one target. Hit: 38 (4d12 + 10) bludgeoning damage.

Fire Breath (Recharge 5-6): The Warlord Oni exhales fire in a 60-foot cone. Each creature in that area must make a DC 25 Dexterity saving throw, taking 70 (20d6) fire damage on a failed save, or half as much damage on a successful one.

Flames of Fury (1/Day): The Warlord Oni can use a bonus action to engulf itself in flames, increasing the damage of its melee attacks for 3 of The Warlord Oni's turns. While engulfed in flames, the Warlord Oni deals an additional 14 (4d6) fire damage with its claw and glaive attacks. In addition, any creature that hits the Warlord Oni with a melee attack while it is engulfed in flames takes 14 (4d6) fire damage. Once the flames have been used, the Warlord Oni cannot use this ability again until it has completed a long rest.

Parry: The Warlord Oni adds 5 to its AC against one melee attack that would hit it. To do so, the Oni must see the attacker and be wielding a melee weapon. 

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

Attack: The Warlord Oni makes one claw or glaive attack.

Cast a Spell (Costs 3 Actions): The Warlord Oni casts one of its innate spells.