Did you see Overlord, the gnarly Word War II zombie-horror-action hybrid from 2018? You absolutely should, as everyone in the Collider Slack agrees that it rules much, much harder than folks gave it credit for. Lucky for all of us, Overlord's director Julius Avery has a new film forthcoming: Samaritan, an original superhero thriller starring Sylvester Stallone as a retired hero. And lucky for Stallone, per Deadline, the rest of the cast has just been formed around him. As the retired superhero, Stallone will be sought after by a younger boy searching for him, unsure if he'…