@ Ian-S: You are exactly right about those time remnants. They make no sense. They're basically a plot device. Deus ex machine, if you will.
They say that time remnants are the past selves of a speedster. They go back in time and bring along that version of themselves. There is just one big plot hole in that: If they go back and "kidnap" themselves from the timeline that means that they broke their own timeline, therefore if the time remnant dies or doesn't go back to his respective timeline, then that should create a paradox or erase the speedster from existence. Unless in the universe of the Flash time is similar to the time in Stephen Kings: Langoliers, where the past gets eaten by giant Pacmans with shark teeth. But I don't think so, because they couldn't travel to the past then, or they could but it would be empty or already eaten and they would just fell in to the empty nothingness and vanish.----> OMG... 2024: Flash vanishes in crysis. The langoliers will get him...XD