All these worlds colliding kind of reminds me of the now dead (in the US / Global at least) mobile game Crossing Void. At the very least, I recognize Index and Heavy Object from that game. That game had a bunch of characters from the same publisher crossing over into a unified game / story world. That included Index / Railgun, Sword Art Online, Heavy Object, Toradora, etc.
If it sounds fun, it actually wasn't. It shut down pretty fast. Lots of grind, not enough story, and the gameplay was just okay. Those who didn't get to play it: you didn't really miss out. Probably some videos of it on Youtube if you're curious.