After Spider-Man and the X-Man Wolverine apprehend the mutant Mesmero, the vengeful super villain uses his mental powers to switch their personalities, creating a serious identity problem for the two so different heroes.
Another new villain dubbed Mesmero switches the minds of both Spider-Man and Wolverine in an attempt to take over New York. Both heroes must adjust to their different powers and mindsets to defeat Sabretooth and to get Mesmero to switch their minds back.—Wikipedia