Imported this Pokemon from Showdown text over a gen6 Pokemon used as the base. It listed Bullet Punch as a relearn move. After switching Scizor to non-mega, removing Bullet Punch from the relearn list, and clicking on relearn moves fixes this issue.
Imports just fine if you remove the -Mega from the set; PKHeX attempts to make the PKM as legal as possible (which includes applying any suggested relearn moves).
Imported this Pokemon from Showdown text over a gen6 Pokemon used as the base. It listed Bullet Punch as a relearn move. After switching Scizor to non-mega, removing Bullet Punch from the relearn list, and clicking on relearn moves fixes this issue.
Thank you for taking the time to read this! And for all your work on PKHeX.