Hey everyone! I've been building a local split-screen co-op mod for the original Oblivion (2006 GOTY on Steam, not Remastered).
Player 2 picks up the second controller, presses Start and joins with their own character: race, class, birthsign, inventory, levels, all saved with your game. Then you play the same world together: fight with your own crosshairs, revive each other when someone goes down, ride two on one horse, and open your own menus while the world keeps going.
It's still a beta (0.9.2 just went up with fixes from the first player reports), so expect a few rough edges. Bug reports are very welcome!
Links and requirements in the comments.-