Dominions (Dominions 6 just came out, but it's an iterative game so try 4 or 5 first)

So it's like civilization and battle simulator had a baby, where armies are managed by the unit and there are simulated battles of thousands.

But all the civs are loosely based on different existing mythologies and there's a crazy complex magic system

Oh, and you get to create a god that you can totally battle with.

If you like civ-like games, it's a really unique and satisfying twist on the genre with an incredible amount of sheer depth.