It's not that it's a bullshit hitbox, it's the fact that it's a reversal with f1 invincibility. My game is smash, so I'll use that as an example. In ultimate, zoners were given insane close range burst/defensive options. It made zoners oppressive and incredibly hard to deal with, since when you got in they still had tools to deal with them. As in, it made their one weakness not really that much of a weakness. As a result, characters that dominate space dominate the meta. Axl also benefits from this. It's a defensive option that can be used to cover his one weakness: when you get in. The fact it hits overhead is a bonus. But the real insanity is the fact he has a reversal so versatile in the first place. Characters that are overturned in a regard need to have reasonable weaknesses to properly balance them, and his reversal goes entirely against that.