Mr. M inside 4D Tower.

Mario turned into Mr. M after he was kidnapped by Dowser while examining mini-Castle Bleck and hypnotized by Dimentio. While he was hypnotized Stario,Quario, and Quinario passed out until he turned back into Mario. He, Dowser and Bob-omberman kidnapped MarioMario54321 while he was waiting for 80 D-Stars.Himself and Mr. Mx2 turned back into their normal selves when Luigi and Starman3 went to go battle Dimentio.