Uni-Dragon

Celestial Weapons. All of the uni-dragon's attacks do an extra 36 (8d8) radiant damage (included in the attacks).

Multiattack. The uni-dragon makes three attacks: one with its horn, and two with its claws.

Horn. Melee Weapon Attack: +11 to hit, reach 5 ft., one target. Hit: 16 (21d10 + 5) piercing damage and 36 (8d8) radiant damage, or heal the same amount of radiant damage, with no slashing damage dealt.

Claws. Melee Weapon Attack: +11 to hit, reach 5 ft., one target. Hit: 30 (5d10 + 3) slashing damage and 36 (8d8) radiant damage.

Breath of Holy Fire (Recharge 5-6). The uni-dragon exhales fire from the heavens in a 50-foot cone. All creatures in the cone must make a DC 19 Dexterity saving throw, taking 80 (16d10) fire damage and 80 (16d10) radiant damage on a failed save, or just the radiant damage on a successful one

The uni-dragon 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 uni-dragon regains spent legendary actions at the start of its turn.

Attack. The uni-dragon makes an attack.

Fly. The uni-dragon moves up to half its flying speed

Tail.  Melee Weapon Attack: +11 to hit, reach 5 ft., one target. Hit: 30 (5d10+3) bludgeoning damage and 36 (8d8) radiant damage.