A few months back I posted my theory on why the current Eon is different to the one in race against time. I recently rethought the issue and changed it slightly. So I'll explain mine and let me hear yours.

In my last theory, following the explanation we have of current Eon, RAC Eon was knocked into another timeline and supposedly faced Ben prime. However, in the episode Eon returns in UAF, we have things that seem to surprise ultimate Ben. He did not seem to know about the identities of Eon's goons and was missing a few key details. So it means things changed ever so slightly for some reason. That would be because the Eon he faced then was not the same as now, as the aforementioned time terrorist states.

Perhaps in the original version of the that episode, Eon was once again knocked into another timeline following his defeat. In the new world, he met a Ben 10 who had his omnitrix destroyed. Perhaps it's the world Eon took Paradox to in omniverse. He mentored that Ben, perhaps hoping he'd take revenge for him and so helped him build the omnitrix into a version of the gauntlet we see in omniverse. However, this Ben betrayed him and absorbed Eon's abilities and took his name.

Then perhaps he decided he would try retracing the originals path, hoping to defeat prime Ben with a surprise change.

All to restore his timeline, one where he rules, as he stated.

All this is speculation of course, just tried to make a theory that follows what is stated. Which is confusing.

What say you all?