Deadpool, since the only way to kill him is with weapons that are made an extra-demesional metal that has the unique effect of being able to shut off regeneration. And none of these listed combatants has ever had access to it besides deadpool, and to say they could take it from him is a laugh because compared to whats shown on this list deadpool is god-teir even compaired to something like oryx(the god of other hive gods). That and he could simply not bring it into combat with him. EDIT: On top of this deadpool has an infinity gem that lets him warp continuity(this is a thing, seriously) he could change the origins of anyone or back storry, or weakness', etc... It effectivley enhances his power to break the 4th wall and access the 5th demension and control the story as he see's fit. If you follow the marvel comics adamantley, or are just plain nerdy like me, this effectivley gives him equal status with THE ONE ABOVE ALL, which is the meta-physical embodiment of stan lee in the marvel multi-verse.