Wings of the Swarm (a.k.a. Blade Wings) are a vanity item for Diablo III. They are granted to players who purchased the Collector's Edition or Digital Deluxe version of StarCraft II: Heart of the Swarm.
When used, they apply or remove a pair of bladed wings resembling those of Sarah Kerrigan.
When obtained, they can be added to the Wardrobe. Only one set of Wings can be used at a time. If equipped, they will be visible even in character selection screen.
Your mind expands, as though you are connecting with millions of other minds across the distant stars.