Sonic, Freedom Planet ,dragon ball and RWBY all characters: Gohan: So, wait... Trunks, I'm curious. If you came back in time again to help us, does that mean we already failed? Trunks: Actually, turns out that's not how time travel works. "Exactly." Silver agreed. "Trust me, I tried." Krillin: So you're saying I can't just take your time machine, go back in time, and tell myself not to date Maron? Trunks: I don't know who that is. But no, you couldn't. I mean, you could, but it wouldn't be the same you. You see, when I travel back to the past, I'm technically going to a different universe... "Does he mean..." Eggman wonders. Gohan: Oh, you mean multiverse theory? Trunks: Wait, what? "What?" Everyone, minus a few, question. Unaware of such a theory. Gohan: Yeah. (cuts to a chalkboard and it shows what Gohan is explaining) With every decision, it creates a branch in the timeline. Whenever you travel back in time, you're actually entering another parallel universe. "I'd never thought to get taught about a science lecture during an anime series." Ruby mentioned, with disbelief. Trunks: How could you possibly-? Gohan: I've been studying theoretical physics. Although, at this point, I guess it's just physics.