Honestly, I don't believe that a superpower would emerge after the collapse of the west. The world would most likely return to a "polar" state, probably focused around Russia, China, Maybe India, perhaps a particularly significant European country/ U.S. successor.
I'd imagine that if a dominant power of that period would emerge, it would be either whatever the strongest successor state to the U.S. is, or perhaps a European country like France or Britain.
Honestly, the more interesting period would be soon after the collapse of the current world order. Depending on how the U.S./West collapses, either Russia or China will end up being on top. Russia seems to depend on the West less than China currently does, so in a fast collapse/civil war scenario, I would point towards them. Slow burn, China.
India would probably be successful, but there's a good chance that a conflict with Pakistan and China would cripple them. China would not emerge unscathed however, and would most likely lose several important population centers.
Africa would be recolonized by China, the Middle East would devolve into total warfare, Japan would contain China decently and might fuck around in SEA, but wouldn't be a significant factor worldwide. Latin America would continue to be irrelevant, and the Jews would probably profit from all of this.