Dominions

Dominions is a fantasy game about gods wanting to become the supreme lord of creation. And not the lazy, stay-at-home gods that getting fat off prayer and amborisia. No, it's about angry gods who are willing to take a shit on the entire world to become head honcho. Much like the Soviet Union, the various nations despised each other but were held together by a powerful leader known as the Pantokrator until he disappeared.

Anyways, what's unique about these gods and the factions they lead is that they tend to be more based upon world mythology and culture than your Tolkien-esque elves and dorfs (though it could be argued he stole it from Norse myth anyways). So there's your Irish Fae, Greek Hoplites, Roman Legionaries, German barbarians, Egyptian er...Lizardmen and mummies, Irish giants, Norse giants, Biblical giants, Sumerian giants, Japanese oni, and more! The exception being most noticeably R'lyeh and their Aboleths and Illithids.

And yes, you can have totally ridiculous battles like Cthulhu vs Spanish Inquisition vs Monkeys vs Zombie Jesus. And yes, you can cast totally ridiculous spells like making a second sun (or turning it off), freezing the oceans, accelerating time so everyone ages to death, poisoning all the magic in the world so horrible horrors eat all mages, etc. Battles in the game tend to start off pretty tame with small armies hitting each other with weapons, then big armies throwing magic at each other, and then huge armies led by insane undead gods. A logical progression in a war of gods.

It's primarily a multiplayer game, since the AI is to dumb-dumb to comprehend what to do, so it just throws shitty units at you.