Very, very interesting question and theoryYou know, when I started this fusions, I never looked at them as characters with a background, instead, I always consider them as... well, fusions xD Like Gogeta or Gotenks, no background, just the fusion between two characters. But now, as more and more people start to ask me about this characters backgrounds, I'm starting to think that's indeed a cool way to look at this fusions. Like they belong to their own universe.With this said, I really don't know the answer to your question... Sageta's little brother from a different future where Goruto died from a disease and everything was taken by the Akatsuki, that sounds awesome! Then... let's see... Knowing he could not defeat the whole organization by himself, Truntachi enters the Akatsuki to destroy it from the inside. And then, for some reason, he figures he needs to go back to the past to change something, probably something that has to do with killing someone. Like Kid Goruto... Since Kid Goku is the reason why Dr.Gero wants revenge.Ahahah Random thoughts xD