Mimicry. The raven can mimic simple sounds it has heard, such as a person whispering, a baby crying, or an animal chittering. A creature that hears the sounds can tell they are imitations with a successful DC 10 Wisdom (Insight) check.

Spellcasting. under the control of a higher being this swarm has the ability to mimic spells as well as cast its own. This swarm is Controlled by Horizon lich which is a level 18 spellcaster. if these spells get used, the spell slot is consumed on the Horizon lich.

9th lvl Unique Spell. (one slot) Raven's Shadow. Choose a target character, target character rolls a DC18 constitution roll. If successful, the spell is nullified. If failed, the target character will have a raven attack it every turn until the accursed swarm dies.

If the raven gets killed by the player have them roll another DC18 Constitution roll with the same rules applied. If successful the spell is nullified, if failed the raven is replaced with a new one.

Beak. Melee Weapon Attack: +4 to hit, reach 45 ft., one target. Hit: 4 piercing damage.

While in a swarm. Swarm. Melee Weapon Attack: +4 to hit, reach 60ft., one target. Hit: 4d6 piercing damage.

Steal. A raven leaves the horde and attempts to steal your weapon from your hands. roll a DC14 strength save. If successful keep your weapon, if failed the raven will steal your weapon and it can be retrieved if you defeat the Accursed flock.

Incredibly weak to fire, Despite the volcanic region where this swarm originates from, throwing alchemists fire at it is sure to do huge damage.

Alchemists fire weakness:  If hit with alchemists fire on a regular alchemist fire attack, roll an additional 1d20 damage for the next 3 turns. At higher levels with customized Hp roll 1d20 for 4-5 turns, DM's Discretion.

Wingstroke Umbra (costs 1 action)  Shadows fill the sky and blot out the sun, roll a DC20 INT save, If successful you are not blinded and do not suffer necrotic damage. If failed you are blinded for 2 turns and roll 3d12 necrotic damage.