Or maybe Ollie trained Barry again in the future sometime and Barry got an arrow to his face, an anti speed force arrow courtesy Ray Palmer, and he became so mad over Ollie because Iris left him, so he killed her and is now searching for present Ollie. #15stepsahead

Hope the Arrow writers don't get an idea from here. I don't wanna see present Ollie vs Evil Ollie from the future or anything. But hold on, this seems more plausible than Barry being Savitar, cause Ollie has gone through some batshit.

Barry should have visited 2024 Ollie, see what's up with his mentor bestie ? #Selfishbarry