Casca is the Roman soldier cursed by Christ in AD 32. He can't die. He goes through the centuries traveling all over the world as a mercenary.
This is a series of books now numbering over 50. It would make a great TV series where every season could cover one book. History Channel or SciFi Channel would work. Might be good for CW or TNT.
It would take a young and upcoming actor to start w current young actor comes comes to mind. It would actually be best to have an unknown. Supporting cast would change from season to season as they'd be in different times and locations.
I don't think they'd make good movies over the long term. Think Conan movies. One or two and then they stop. A series would be better.