Well the feats says that kumagawa never showed the full potential
It's also come with him erase the concept of colour inside his own verse but that doesn't state the full potential of all fiction
But why it is reconsider as Low 2-C as it never shown full potentially
And about medaka box verse there isn't Multiverse but omniverse, we can tell that kumagawa read his shounen jump and Ajimu is aware of the real world ( also him talking about goku which is him talking about other verse )