5) T-Ray
Outside of Ajax, T-Ray is perhaps Deadpool’s greatest enemy, so pitting these two against each other in the sequel would definitely work. Of course, the movie would probably have to drop the fact that he claims to be the real Wade Wilson, as it would really complicate everything we saw in the first movie, but that does have at least some potential depending on how the writers go about handling it.
Regardless, T-Ray is a truly sadistic and twisted mercenary, and playing on their history (even if it’s one which is newly created for the big screen) could lead to him being a really interesting protagonist for this movie.
At one point, T-Ray uses magic to resurrect the Merc with a Mouth’s dead wife – could that be a way of creating Copycat? – making things between these two really twisted and personal. As Deadpool doesn’t exactly have a massive rogues gallery, T-Ray seems like the natural choice of villain for the next movie in this franchise, and there are definitely a lot of great places he could be taken.