His immortality is later brought up when the time - traveling Jon Spectre hints at Sam 's important role in the distant future .
Cannonball 's existence as an External is disputed by Selene .
Cannonball 's immortality is later brought up when the time - traveling Jon Spectre hints Cannonball Sam 's important role in the distant future .
Cannonball 's existence as an External is disputed by Selene .