1 {scene: The Infinite Featureless Plane of Death}
1 Me: Wait. There's a problem here. The copy of me who killed me wasn't decayed. I'm partly skeletonised already.
2 Death of Insanely Overpowered Fireballs: Oh. It's the mess-up in the time stream. I'll have to come back earlier. {vanishes suddenly}
3 Me: You'll have to whuh...?
4 {scene change: The Infinite Featureless Plane of Death, earlier}
4 Death of Insanely Overpowered Fireballs: {manifesting suddenly} Ah, there you are. I told you I'd be back.
4 Me: {not decayed yet} What? Who are you?

2021-03-27 Rerun commentary: This is how you wallpaper over a continuity error. You have a character notice it, and then come up with an explanation.

Now it doesn't have to make sense!