Apollyon

Innate Spellcasting. Apollyon's innate spellcasting ability is charisma (spell save DC 15, +7 to hit with spell attacks). She can innately cast the following spells, requiring no components:

3/day each: dispel magic, find greater steed, crusader's mantle

1/day each: destructive wave, banishing smite

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

Martial Advantage. Once per turn, Apollyon can deal an extra 14 (4d6) damage to a creature she hits with a weapon attack if that creature is within 5 feet of an ally of Apollyon that isn’t incapacitated.

Shoulder Bash. If Apollyon hits a creature at least twice with a melee weapon, she can make a shove attack on it as a bonus action.

Survivor. Apollyon regains 10 hit points at the start of her turn if she has at least 1 hit point but fewer hit points than half her hit point maximum.

Unyielding. Apollyon has advantage on saving throws against being frightened. She can also roll a 1d6 and add the result to any saving throw.

Multiattack. Apollyon makes three melee attacks.

Aragon Blade. Melee Weapon Attack: +9 to hit, reach 5 ft., one target. Hit: 12 (2d6 + 5) slashing damage.

Battlefield Cunning (Recharge 4-6). Up to two allied creatures within 60 feet of Apollyon that can hear her can use their reactions to make one melee attack each.

Rouse The Wolves (Recharges after a Short or Long Rest). For 1 minute, Apollyon can utter a special command or warning whenever a nonhostile creature that she can see within 30 feet of her makes an attack roll or a saving throw. The creature can add a d4 to its roll provided it can hear and understand Apollyon. This effect ends if Apollyon is incapacitated.

Riposte. When a creature misses Apollyon with a melee attack, she can make a melee weapon attack against the creature. 

Apollyon 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. Apollyon regains spent legendary actions at the start of its turn.

Weapon Attack. Apollyon makes a weapon attack.

Command Ally. The warlord targets one ally it can see within 30 feet of it. If the target can see and hear the warlord, the target can make one weapon attack as a reaction and gains advantage on the attack roll.

Frighten Foe (Costs 2 Actions). Apollyon targets one enemy she can see within 30 feet of her. If the target can see and hear her, the target must succeed on a DC 16 Wisdom saving throw or be frightened until the end of Apollyon's next turn.