I don't know where to start when it comes to Paradigm Worlds, a mod for Mount & Blade: Warband. Here's a trailer. The trailer is actually 4,000 screenshots strung together. I don't know why. It's perhaps appropriate, though, as the mod itself is in fact many different mods—and universes—flung together.
Here's a snippet of the summary:
Steampunk conspiring againt XV century Europe, Aliens fighting Djiniis, Orc fighting Morloks, Uruks fighting agains Alien Pirates! Swords, Axes, Lightsabers, Flintlock, Laser Cannons, Plasma Blasters, Arqebusiers, Blunderbuses...
Fighting over the multiverse are different factions and sub-factions made up from bits of pop culture and history squashed together, so you've got Soviet Steampunks fighting Nazi-Knights, and Jedi-Samurai duelling creatures who came from a Middle-earth where Sauron won.
There's a hint of Ultimate Epic Battle Simulator, but Paradigm Worlds seems to be more than just tossing random armies against each other. There's other weird stuff going on, too. You can buy microchips that augment your troops abilities, for instance, but only if they've got the cybertech skill. Probably not a Roman Centurion, then. But since it's also possible for every unit to mutate into a completely different species, who knows?
Speaking of transformations, your troops might just become skeletons. "This is a final form for every living organism," the mod's creator explains. Every time a unit switches species, there's a chance it will just shed its body and become a walking bunch of bones. There's no way to mutate past that. There are other kinds of undead, too, and between mutations and the factions, you can end up with some truly weird combos.
Around 30 different skills and attributes can enhance your army of displaced warriors. While anyone can apparently pick up a machine gun and use it, only units with a specific skill can use it effectively, with the skill improving their aim and the recoil. Those things are also affected by the weather, which can change every hour. Biomes have default temperatures, visibility and chances for different types of weather.
The story is still in development, but apparently all of the titular Paradigm worlds are close to destruction because there's too much "hate, evil and cruelty". It's possible to act like a jerk, enslaving people, bribing and munching on some long pig, but all of those things push the Doomsday Clock closer to the end. It's always moving forward, unless you perform some very good deeds to kick it back a bit. "Every day is a single click," the mod's creator warns. "A click to hell." I love it.
Paradigm Worlds launched in 2017, but most of the features above were added in a recent update. You can check out the very detailed update post on ModDB, where you can also download the mod.