User blog comment:Master Sima Yi/Assassinews 27-08-'15 – First look at Michael Fassbender in the Assassin's Creed film/@comment-3163807-20150828030420/@comment-733050-20150829115452

They could lay the groundwork for later films by having Fassbender reprise the role of Callum but not play his ancestor. Keep it fresh each time, having an established actor like him help an unknown get a big role (kinda like how Harrison Ford returning to Star Wars allows JJ Abrams to cast John Boyega as the protagonist).