So, it turns out you're not supposed to shoot the guy who everyone thought was you in the forehead. They patch him up and put him in the bathtub while Black Swan explains that in the explosion at the end of Deadpool v3, Black Swan's powers overexerted themselves to save his life. He, Deadpool and Niho all gained pieces of DP's healing factor and Alex wound up with most of Black Swan's personality trains, as well as his skill with guns. They all go to the theme park and decide to switch everyones' minds around so that they're all correct again. It works, but it works a little too well. Black Swan absorbs more power than his fill and starts going on a rampage. He knocks out Alex and treatens Sandy before being stabbed through the back by Deadpool.