Conspiracy of Ravens (HB)

You target a creature within range and summon a Swarm of Ravens to appear in the same space as itself. The swarm disappears if it is reduced to 0 Hit Points or when the spell ends. The swarm shares your Initiative count, but it takes its turn immediately after yours. It obeys your commands (no action required by you). If you don't issue any, it takes the Dodge Action and uses its movement to avoid danger. While another creature is in the swarm's space and the swarm has half its Hit Points or more, that creature is Blinded.

Using a Higher-Level Spell Slot: When you cast this spell using a spell slot of 4th level or higher, you summon an additional swarm of ravens at a target's space for each 2 slot levels above 2nd.