Fiendish Blessing. The AC of the cambion warlord includes its Charisma bonus.

Innate Spellcasting. The cambion warlord’s spellcasting ability is Charisma (spell save CHA DC 18). All spell saves (ignore what is listed in the spell description) are CHA 18. The cambion can innately cast the following spells, requiring no material components:

3/day each: alter self, command, fireball

1/day: cone of cold

Cantrips (at will): chill touch, fire bolt, ray of frost, minor illusion, true strike

1st level (4 slots): comprehend languages, shield

2nd level (3 slots): mirror image, misty step, see invisibility

3rd level (3 slots): fireball, dispel magic

4th level (2 slots): wall of fire, greater invisibility

Multiattack. The cambion warlord makes two melee attacks or uses its Fire Ray twice.

Hellrider's Greatsword. Two-handed Melee Weapon Attack: +12 to hit, reach 5 ft., 1 target. Hit: (2d8 + 7) slashing damage, plus (1d8) fire damage. Critical on 19 or 20. On Critical add (1d8) of any type of damage you choose.  

Fire Ray. Ranged Spell Attack: +10 to hit, range 120 ft., one target. Hit: (3d6 + 5) fire damage.

Fiendish Charm. One humanoid the cambion warlord can see within 30 feet of it must succeed on a CHA DC 18 Wisdom saving throw or be magically charmed for 1 day. The charmed target obeys the cambion warlord’s spoken commands. If the target suffers any harm from the cambion or another creature or receives a suicidal command from the cambion, the target can repeat the saving throw with disadvantage, ending the effect on itself on a success. If a target’s saving throw is successful, or if the effect ends for it, the creature is immune to the cambion warlord’s Fiendish Charm for the next 24 hours.

Immolation:  Flames wreathe any creature(s) of your choosing within a 30 ft radius (90 ft range). The target must make a CHA DC 18 saving throw. It takes 10d6 fire damage on a failed save, or half as much damage on a successful one. On a failed save, the target also burns for the spell’s duration. The burning target sheds bright light in a 30-foot radius and dim light for an additional 30 feet. At the end of each of its turns, the target repeats the saving throw. It takes 6d6 fire damage on a failed save, and half damage on a successful one. These magical flames can’t be extinguished by nonmagical means. Creatures must leave spell's radius in order to save. If damage from this spell kills a target, the target is turned to ash.