A mod based on Robert E. Howard's Hyboria setting would be awesome. The multiplayer and singleplayer would be some kickass fun. I can already see a bunch of cool factions now eg- Aquilonia, Cimmeria, Stygia, Gunderland, Hyperborea, Khitai, Picts, Vanir, Nemedians. Then I can finally lay waste to the world with hordes of Pictish scouts firing deadly volleys of arrows