Subspace
Subspace is a strange realm which features in the Subspace Emissary. It can be used as a destructive force by the Subspace Army in SSBB. It is utilized in the form of a Subspace Bomb , which is triggered by two R.O.B. Sentries. A timer then begins counting down. When it reaches zero the bombs true power is unleashed and it creates an antimatter vortex that sucks in matter from the World of Trophies. The hole expands in all directions while sucking in matter at the same time. Later in the story, the subspace bomb is surpassed by a machine with a similar function: the Subspace Gunship, a large armed cannon that shoots the same antimatter as the Subspace bomb. Master Hand is shown to inhabit this realm as well as Tabuu. Tabuu receives what has been taken from the world by the Subspace bombs and uses it to make The Great Maze.
This is different from the Subspace of Super Mario Bros. 2.
