Given that Vegeta has been a Space Pirate, he already crossed the line multiple times in his life. But the Saiyan Prince has three candidates:
MEH means the point they're established as irredeemably, permanently evil, so Vegeta making a Heel–Face Turn disqualifies him (thinking he didn't deserve redemption after that is another separate issue).
MEH has to be intentional by the narrative. It is only subjective in if it is bad enough to so change their portrayal or where they cross it if they have multiple candidates.
Per ATT
, removed this:
MEH means the point they're established as irredeemably, permanently evil, so Vegeta making a Heel–Face Turn disqualifies him (thinking he didn't deserve redemption after that is another separate issue).
MEH has to be intentional by the narrative. It is only subjective in if it is bad enough to so change their portrayal or where they cross it if they have multiple candidates.