Void (dimension)

The Void, often referred to as interdimensional space, is the space between the assorted universes and dimensions of the BZPB Omniverse. It is also what separates the BZPB Omniverse from other omniverses (or multiverses).

In its natural state, it contains nothing: no color, no matter, no light, no time. For this reason, staring at the Void for extended periods of time is said to cause insanity.

It is often accessed by interdimensional travellers when crossing from one universe to another, though the Void can be bypassed by teleporting directly into whatever universe they wish to travel to.

Visitors of the Void

 * In the dramatic finale of Dark Mirror, Takanuva used his Kanohi Olmak to escape through a portal to the Void, but Tuyet clung onto his leg in an attempt to stop him. However, the portal closed when she was halfway through, slicing her body in half. Tuyet's top half is currently still floating in the Void, complete with her Mask of Intangibility and fragments of the Nui Stone still embedded in her chest.
 * TMV and his allies once found themselves in the Void. When Blackout realized where they were, he sent some Pokémon after them. Hilarity ensued.
 * The Observers have a space station in the Void from which they observe the development of several different universes. When they want to observe time instead, they use their station in Chronospace.
 * Mazkertis was imprisoned in a nether cell in the Void for five decades. This probably didn't have a good effect on his mental health.
 * The Universal Union of the Combine routinely travel through the Void, seeking out new universes to conquer.