Time travel character generation idea:
All the PCs are the same historical person, but from different timelines. To begin the game, you establish 5 facts that everyone knows about that person. (These don't have to be true, maybe Napoleon really was extremely short in most timelines, just not ours. but they need to be common knowledge about that person.) So for Amelia Earhart, you might have facts like "daredevil pilot" and "disappeared flying over the ocean".
Once you have those five facts, every player will create their specific version of the character. You have several responses, that you distribute between them. "Yes, and...", "Yes", "Yes, but...", No, but..." and "No, and...". Choose one response to match each fact, then finish the sentence. e.g., "Yes, I was a daredevil pilot, but it wasn't with airplanes. On our world, we had giant insects that I helped tame and turn into useful flying mounts." "No, I didn't disappear flying over the ocean, and I became famous as the first person, man or woman, to circumnavigate the globe by air."
So everyone gets a character that is recognizably that historical person, but also is weird and different than the other PCs.
Variant: instead of always having one of each response, you could instead roll some dice. 1=No, and 2=No, but 3=Yes, but 4=Yes 5=Yes, and 6=player's choice.
Come to think of it, this is also ready made for an Into the Spiderverse / Crisis on Infinite Earths / What If...? / Batman Who Laughs superhero game, where everyone can play variants of the same superhero.