It might actually be bad for him, though. His ability is derived through cancer. Cultivation is all about enhancing the body, removing impurities, modifying the cells to the max, and evolving into a higher being. Cancer would be one of the things removed, right?
You got a point but his cancer is mutated alas became part of his body so who knows how it will play out, not to mention, cancer aside but imagine a character like that in a cultivation world (4th wall breaking, not respecting the elders and probably playing around with the jade beauties but most of all that strange psychopathic behavior that somehow retains some logic and comedy, so, yeah cancer or not, I believe a character like that in a cultivation based world will mostly be an interesting addition to a cultivation world )
Superman would probably beat most cultivators to a pulp like they were nothing. But he can't do anything about the super high level cultivators that can create universes and what not... Unless you use the version of superman that can bend reality at his will and stuff that is... In this case it's impossible to know who wins.