You do know Acheron's transformation to her Unsheathed Sword from her base one is like a massive speed gap right especially if Acheron literally sees the entire Astral Express and Aventurine even other things as slow-motion and
well there are problems with Speed Equalization as a rule in itself
Acheron literally jumps from FTL to MFTL+, and since Speed Equalized only takes the first part in which both characters are FTL, yeah Acheron's blitzing Reinhard not to mention the AP difference and her hax

If you're restricting Unsheathed Sword, just make it a sword combat fight like Acheron and Reinhard clashing but Acheron definitely one-shots anyway so gg