As for The Flash, Miller has already cameoed as the Scarlet Speedster in Batman v Superman: Dawn of Justice and Suicide Squad, but Justice League will be the character’s official debut.
Ezra Miller’s Credence is one of Fantastic Beasts and Where to Find Them’s more mysterious characters.
Credence is also someone who could become “notable” within the Wizarding World, which could mean Miller is already slated to appear in Fantastic Beasts 2.
Miller will then lead the Flash movie in 2018, appearing alongside Kiersey Clemons and potentially Billy Crudup.