in my opinion, a person who was able to go to the end of his trials should have 90%+ mastery in their body. with that being the case, the only reason they would be unable to triumph over enemies would be that their stats (body) do not follow their understanding (i.e. being unable to follow an opponent's movement even though that movement is something they can overcome). MC should have used greed's skills to optimize their senses/perception + their reaction/body. that would be the minimum for them to not be too OP.
