Oh yes, I can explain.
Basically, Mephiles is a villain that originally appears during a time where the verse is rated High 3-A. However, as a time travel story, he reappears in a boss fight when the protagonist received several amps and is at least 2-C.
The vast tier gap was originally proposed to be amended with a separate key, as the villain displays various abilities innately that previously required verse-related amps.
However, it was decided early on in the thread that Mephiles would be handled in a separate CRT because it was divisive on how to handle it. Technically, the changes to implement a key aren't approved and requires a follow-up CRT.
The person who applied the key is simply jumping the gun, but not maliciously. It seems to have been a misunderstanding.