The Different- Dimension War is the name given to the endless feud between Barian World and Astral World that serves as the central problem within Yu-Gi-Oh! ZEXAL anime. The Earth is part of that war as a major battlefield, with some caught in the feud such as Yuma Tsukumo. All three worlds seek for the Numeron Code which can put this endless feud to an end. According to Misael, the Barian World sustained feud due to if they do not, then their own world will have "no future".
Eons ago, Astral battled against Don Thousand in the far sky of Earth. The lasted for hundreds of days causing choas on Earth such as Rains of fire pouring down on the grounds as lightning ripped through the very Earth. Finally, two collided and Astral emerged as the winner. He then seals Don into the Sea of Ill Intent in the Barian World as a prisoner. During the final battle, a shard of Don's malice got stuck inside of Astral creating "Number 96: Dark Mist".