5) X-Force
Deadpool has fought both with and against X-Force over the years, and if that long rumoured movie focusing on the team is ever going to happen (last we heard, Kick-Ass 2‘s Jeff Wadlow was supposed to be writing the script), then laying the groundwork in the Deadpool sequel makes perfect sense.
That could consist of introducing characters from the eventual spinoff or even having an early version show up to fight Wade before he ultimately ends up joining them, but with Hugh Jackman moving on from Wolverine, having Ryan Reynolds’ Merc with the Mouth be a focal point of X-Force would be a smart move by Fox.
As part of the most recent iteration of the team who deal with the jobs too violent for the X-Men, Deadpool got the chance to show off a different side of himself and proved to be a surprisingly valuable part of the group.