Aura of dread. Creatures within 30 feet of the abyssaryn must succeed on a dc 18 wisdom saving throw when they encounter the Abyssaryn or become frightened for 1 min. A creature that succeeds on the saving throw is immune to this effect for 24 hours.

Legendary resistance(3 uses a day). If the Abyssaryn fails a saving throw, it can choose to succeed instead

deathly wings. The Abyssaryn ’s wings emit a chilling, spectral aura. When the Abyssaryn flies it can use its bonus action to create a 15-foot-radius area of necrotic energy centred on itself. Creatures within this area take 10 3d6 necrotic damage at the start of their turn. (2 uses every long rest)

undead nature. The Abyssaryn does not require an food, water, or air

multiattack. The Abyssaryn makes three attack: one with bite, one with claws, and one with tail. (If uses action, the Abyssaryn can’t do anything anything else for the rest of its turn)

bite. Melee weapon attack: +11 to hit, reach 10ft, one target. Hit: 17(2d10+6) piercing damage. Plus 7 (2d6) necrotic damage 

claws. Melee weapon attack: +11 to hit, reach 5ft, one target. Hit: 15 (2d8+6) slashing damage.

tail. Melee weapon attack: +11 to hit, reach 15ft, 1-5 targets. Hit: 18 (2d10+6) bludgeoning damage, and the target(s)must succeed on a DC 18 strength saving throw or be knocked prone.

shadow breath (recharge 5-6 turns). The Abyssaryn exhales a 60-foot cone of chilling necrotic energy. Each creature in that area must make a DC 18 constitution saving throw, taking 49 (11d8) necrotic damage on a failed save, or half as much damage on a successful throw. Creatures that fail the saving throw are also frightened for 1 min. They can repeat the saving throw at the end of each of their turns, ending the effect on themselves on a success.

Enter the description for how bonus actions work for your monster here.

Reaction Name. Enter the description for your action.

The Abyssaryn can only use legendary actions one at a time and at the end of another creatures turn. The Abyssaryn regains spent actions at the start of its turn

tail swipe. The Abyssaryn makes a tail Attack

dark ecscape (costs 2 actions). the Abyssaryn beats its wings. Each creature within 10 feet of it must succeed on a DC 18 dexterity saving throw or take 14 (2d6+6) bludgeoning damage and be pushed 10 feet away. The Abyssaryn can then fly up to half its flying speed

Enter the description for how mythic actions work for your monster here.

Mythic Action Name (Costs # Actions). Enter the description for your mythic action.