Originally posted by AllanklesNo it's not, actually.
This is true.
Anywho, during Mxy's rampage, one of the several universes he destroyed was the DC1M universe - which Prime obviously resides in (circled in red):
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And the end result of said rampage was a void of absolute nothingness (aside from Mxy/Bat-Mite):
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So by those two scans, we can logically say that Prime was erased by Mxy, along with everything else. Therefore, Mxy ftw. 🙂