Cerburs Flameskull

Illumination. The cerberus flameskull sheds either dim light in a 30-foot radius, or bright light in a 30-foot radius and dim light for an additional 15 feet. It can switch between the options as an action.

Magic Resistance. The cerberus flameskull has advantage on saving throws against spells and other magical effects.

Rejuvenation. If the cerberus flameskull is destroyed, it regains all its hit points in 10 minutes unless holy water is sprinkled on its remains or a dispel magic or remove curse spell is cast on them.

Chains of the Nine Hells. Summoning strength from the Nine Hells, five chains of flame crackle and burst from the ground around the caster and rapidly snake along the ground toward up to five enemies the caster can see within a range of 60 feet, leaping towards their target and exploding into a column of flame upon reaching them. Each target must make a Dexterity saving throw, taking 8d6 fire damage on a failed save, or half as much damage on a successful one. Alternatively, all five streaks of fire can instead converge toward a single target, dealing 12d6 fire damage on a failed save, or half as much damage on a successful one. The fire can travel over obstacles up to 5 feet high, and ignites flammable objects along its path that aren't being worn or carried. This ability can be used once per day or can be regained through rejuvenation.

Spellcasting. The cerberus flameskull is a 10th-level spellcaster. Its spellcasting ability is Intelligence (spell save DC 17, +10 to hit with spell attacks). It requires no somatic or material components to cast its spells. The cerberus flameskull has the following wizard spells prepared:

Cantrip (at will): mage hand

1st level (4 slots): magic missile, shield

2nd level (3 slots): blur, flaming sphere

3rd level (2 slots): fireball

Multiattack. The cerberus flameskull uses Fire Ray three times.

Fire Ray. Ranged Spell Attack: +10 to hit, range 30 ft., one target. Hit: 10 (3d6) fire damage.

Fire Breath (Recharge 5–6). The dragon exhales fire in a 30-foot cone. Each creature in that area must make a DC 17 Dexterity saving throw, taking 56 (16d6) fire damage on a failed save, or half as much damage on a successful one.