4) Iris West
This one is admittedly a little out there, but bear with me. When Savitar kills Iris he says that he’s finally free and vanishes in a flash of light; is that because it’s Iris who somehow winds up trapped in the Speed Force? There’s precedent for that happening in the comic books (she even spent a chunk of time far in the future), so killing herself in the past would ensure that she never winds up being trapped in what sounds like a living hell.
This reveal is one the show might struggle to pull off, but if the story is told in the right way, it could actually work really well and shakes the very foundation of Barry and Iris’ relationship to its core. After all, there’s something horribly poetic about the Flash trying to save the life of the woman he inadvertently trapped in the Speed Force. The question is, would a twist like this be too much of a shark jumping moment for The CW series?