The time travel mechanics of The Flash are kind of mind-bending, and I have to hand it to the writers to weave these tales within tales, because they keep me guessing. I've pretty much loved this third season of the Flash, and at times I forget that it's an alternate timeline that shouldn't really exist. But that it does exist should have some kind of repercussion on Barry. I can't help but think how cool it might be that Barry is fighting himself, which is why he can't win.
I know I like to make predictions, especially when I sense that a series is building toward a season finale. So my prediction is that the big bad of the entire season, a.k.a. Savitar, is none other than a Time Remnant of Barry Allen himself.