The Universe Tree (宇宙の木 Uchūnoki) is a powerful object utilized by Fu.
The Universe Tree is a galaxy sized tree that can be used to create an entire universe.
After Hearts' defeat, the Universe Seed grew into the Universe Tree. The Universe Tree absorbs energy from the twelve universes and its inhabitants, the only way to counter this is for an entity as powerful as a God of Destruction to form and maintain an energy shield around the entire universe, as Beerus did for Universe 7. It eventually withered after Beerus made a wish to Super Shenron to destroy its roots, rendering Fu's plans for it moot - until Fu became the Dark King and used its power alongside his and Dogidogi's to create his Pseudo Universe.
Video Game Appearances