There are a large number of alien species that live on another extradimensional frequency. They are usually handled by the Void engineers.

Known Facts
*Reality has more than one layer. Extradimensional entities live in these other realities.
*Some entities invade our reality.
*They have a wide variety of abilities and powers.

Protocol
*Immediately destroy the ones who cross the boundaries of our world.
*investigate, catalogue and report to the Void Engineers.