What if there was something like Smash...but for ANIME?
Sonic and all his friends get together to get ready to raid the Subspace Army's home base, when all of a sudden, the army shows up at the IS Academy to take them down. With the academy gone, they must team up with allies from both their world and other worlds to put a stop to the army before they gain ultimate supremacy across the multiverse.
Based off of Marvel vs. Capcom Infinite's Story Mode, with some changes and additional characters. When Tabuu and Prometheus fuse and merge the Jump and Nintendo universes together, it is up to the Shonen Jump and Nintendo heroes to find the four remaining Onyx Gems to save their worlds.