Fortitudo, Bringer of Flame

Angelic Weapons. Fortitudo's weapon attacks are magical. When Fortitudo hits with any weapon, the weapon deals an extra 7d8 radiant damage (included in the attack).
Divine Awareness. Fortitudo knows if he hears a lie.
Innate Spellcasting. Fortitudo's spellcasting ability is Charisma (spell save DC 24). Fortitudo can innately cast the following spells, requiring no material components:
At will: detect evil and good
3/day each: aid (as 6th-level spell), [Tooltip Not Found]
1/day each: commune
Legendary Resistance (3/Day). If Fortitudo fails a saving throw, it can choose to succeed instead.
Magic Resistance. Fortitudo has advantage on saving throws against spells and other magical effects.
Multiple Heads. Fortitudo has two dragon heads. While it has at least one dragon head, Fortitudo has advantage on saving throws against being blinded, charmed, deafened, stunned and knocked unconscious.
Whenever Fortitudo takes 75 or more damage in a single turn, one of its dragon heads dies.

Multiattack. Fortitudo makes as many bite or magma ball attacks as it has dragon heads.
Bite. Melee Weapon Attack: +17 to hit, reach 15 ft., one target. Hit: 20 (2d10 + 9) piercing damage plus 31 (7d8) radiant damage.
Magma Ball. Fortitudo spits a ball of magma at a creature within 120 feet of it. The creature must make a DC 21 Dexterity saving throw, taking 16 (3d10) fire damage and 16 (3d10) bludgeoning damage on a failed save, or half as much on a successful one.
Bringer Of Flame (Recharge 6 With Two Dragon Heads; Recharge 5–6 With One Dragon Head; Recharge 4–6 With No Dragon Heads). The ground in a 90-foot-radius circle around Fortitudo erupts and is flooded with a 2-foot-deep layer of magma that lasts until the start of Fortitudo's next turn. The magma is difficult terrain and deals 35 (10d6) fire damage to each creature that moves into it or starts their turn in it.
Body Slam. Melee Weapon Attack: +17 to hit, reach 5 ft., one target. Hit: 15 (1d12 + 9) bludgeoning damage plus 31 (7d8) radiant damage. If Fortitudo moved at least 20 feet before the attack this turn, the slam deals an additional 15 (1d12 + 9) bludgeoning damage.

Fortitudo can take 3 legendary actions, choosing from the options below. Only one legendary action can be used at a time and only at the end of another creature's turn. Fortitudo regains spent legendary actions at the start of its turn.

Detect. Fortitudo makes a Wisdom (Perception) check or a Wisdom (Insight) check.
Tail Swipe. Melee Weapon Attack: +17 to hit, reach 20 ft., one target. Hit: 18 (2d8 + 9) bludgeoning damage plus 31 (7d8) radiant damage.
Erupt. Fortitudo chooses a point within 90 feet that is flooded in magma from its Bringer of Flame feature. Flames erupt from that point. Creatures within 15 feet of the eruption must make a DC 21 Dexterity saving throw, taking 35 (10d6) fire damage on a failed save, or half as much on a successful one.