In the comics, the teen hero Invincible teamed up with the heroes of Image Comics’s other superhero books, from Spawn to Savage Dragon to Witchblade. On TV, though, series writer Robert Kirkman advises fans against getting their hopes up; legal issues, rights issues, and all the things you might expect would make porting over guest stars virtually impossible, which likely means that the stories in which other Image heroes appeared will be reworked slightly so that there’s no need for guests, or perhaps given generic guest stars who are clearly intended to be somebody, but are legally distinct from them.