From what I know, it's a dimension that only has Fusion as a summoning method for the game. So XYZ and Synchro would be like that too. Although I'm just guessing here.

Yeah definitely! We could all have fun together. Yuto seems like he needs to smile more too, so I would like to try to make him laugh.

Idk inter-dimensional warfare? I don't like to fight, but Yuto seemed to think Yugo was working with the Fusion dimension and Yugo had some beef with Yuto about stealing something important from him. That's basically all that I know. After their fight, I woke up here.