Board Thread:Questions and Answers/@comment-28265951-20160421125919/@comment-2112031-20160530190930

Having rewatched the scene in which Zoom created his time remnant, I noticed that it's the Zoom that appears that gets killed, not the Zoom that was already there. So, as far as I can tell, it's the future version that gets killed. Still a paradox, but a bit more manageable.

Image two timelines:

Timeline 1: Zoom (henceforth Zoom 1) notices that no future version of himself has appeared and travels a few minutes back in time.

Timeline 2: Zoom 1 arrives next to Zoom 2. Zoom 1 briefly fights Barry trying to goad him into killing him, but Barry still refuses, which results in Zoom 2 doing it for him.