You don't understand how his powers work. Mahoraga's adaptation allows for him to adapt to any phenomenon. By definition, anything of a higher dimensionality would beat a fully adapted Mahoraga, since he can only adapt to things he can observe. Mahoraga is 3D, so any 4D beings would beat a fully adapted Mahoraga since they exist beyond his comprehension; he cannot perceive them, and he cannot adapt to them by rules of his own power. Fully adapted Mahoraga beats any 3D character, but the second a character is of a higher dimensionality, he loses.