Bat Swarm (Lords of Shadow)

Bat Swarm is a sub weapon which fires the bats away in Castlevania: Lords of Shadow - Mirror of Fate and Castlevania: Lords of Shadow 2.

Castlevania: Lords of Shadow - Mirror of Fate
In Mirror of Fate, Alucard gains this "sub-weapon" early after his wake. When walking in a cave, bats start to react to his presence.

Once this power is obtained, Alucard can launch bats in a direct line toward his enemies. Bats attack foes for a few seconds before disappearing. The attack can be charged (by holding the button) and the bats will charge the enemy with more force, sometimes killing it in one hit.

Some enemies are immune to this power, especially the Reaver, who eats bats and spits their bones, potentially damaging Alucard if he's standing close to the him.

Castlevania: Lords of Shadow 2
Acting as a sub-weapon, a swarm of bats can be summoned, aimed and thrown at enemies to "blind" them for a short amount of time. Although it doesn't cause any damage to the target, it can be useful to keep it away while dispatching other enemies. Also, it can be used when stealth is a priority and the player doesn't want to be seen.