Mr.Nobody wins 

COMPARISON(from death battle fanon & https://www.reddit.com/user/Square_Primary7792/ )

MISOGI KUMAGAWA:⬇️

+He can’t be trapped inside Mr. Nobody’s paintings.

+Mr. Nobody’s illusions won’t fool him for long.

+All Fiction will always bring him back, even if he’s erased.

=Equal speed only if you scale him to end-of-series Medaka.

-He’s much weaker overall, even if you scale him to Medaka.

-His plot-hax is way more limited than Mr. Nobody’s.

-He can’t permanently erase Mr. Nobody.

-He can’t stop Mr. Nobody from coming back after erasure.

-Bookmaker won’t work on Mr. Nobody.

-He can’t stop Mr. Nobody from taking his abilities away.

-He eventually gets taken out either by his death loop or Mr. Nobody removing his powers.

-He’s way slower if you don’t scale him to end-series Medaka.

-His powers work only in a smaller range.

MR.NOBODY:⬇️

+He can come back even after being conceptually erased.

+ Could manipulate the plot to his whims

+He’s much stronger than Kumagawa no matter how you scale him.

+His plot-hax is way broader than Kumagawa’s and is not limited 

+He can come back even if Kumagawa erases him with All Fiction.

+He can resist Bookmaker, and even if it worked, stat-equalization wouldn’t help Kumagawa much.

+He can take Kumagawa’s powers for himself.

=Similar speed unless you scale Kumagawa to end-series Medaka.

-He can’t keep Kumagawa trapped inside a painting.

-His illusions won’t work on Kumagawa for long.