The Sunset Invasion is a random event that happens late in the game. Aztec explorers arrive on the shores of Western Europe; their apparent goal is innocuous -- they just want to shift lots of beads. Much like hippy street vendors trying to offload crappy bead necklaces, these Aztecs are not to be trusted. Not long after they arrive, an invasion fleet appears, and all hell breaks lose.

What they lack in technology, they more than make up for in sheer numbers. It's like the whole population of South America decided to take a bloody holiday to Europe. In the game I witnessed, they landed in Spain, and quickly started harassing Castille, Aragon, and Portugal, much to the dismay of those nations. 

In almost no time at all, this war machine had swallowed up most of northwest Spain, and the native powers were doing naught but throwing troops away in a pathetic attempt to slow down their progress. Normally, when one sees an unpleasant neighbor getting schooled by an enemy, it's best to leave them to it or maybe pick apart the carcass. With the Aztecs, however, it's a considerably more international concern. Teaming up against them seems like the smart way to approach the horde from across the ocean.

New unit models and detailed character portraits have been added, giving flavor to these exotic invaders. Leaders wear multi-colored feathered head dresses, warriors dress up in garish and intimidating costumes, and their weapons are a far cry away from the swords and spears of the European armies. 

While they are not playable due to being awful pagans, they still have quite a bit of an impact, much as the Mongols already do. With them, they bring a new disease that ravages their enemies and spreads throughout the lands they attack, and the dynasties of Europe now have to worry about their hearts being ripped out and made as a sacrifice to the Aztec's distant gods. 

Once they settle their new, oppressed provinces, the Aztecs can start to create cavalry and make other advances, increasing their power and the risk of other nations being attacked the longer they linger. Paradox has been working on an oft-requested feature where conquerors can rename captured lands with culturally appropriate alternatives, so Europe may eventually play host to some suitably exotically named provinces that few would be able to pronounce. 

The quirky nature of Crusader Kings II's character creator means that some very unusual Aztec leaders crop up organically. One such leader was the result of an Aztec and Mongolian coupling, and he strutted around with his oh-so fabulous feathered garments, while sporting a very fetching handlebar mustache. That's a leader I can admire.

There's no doubt that it is more of a novelty than serious DLC. It doesn't add much to the core game beyond the typical fixes and tweaks that get added with each expansion, regardless of whether or not one purchases it. Yet with the huge scale of the invasion, there's certainly going to be hours of wars with the blood-drunk would-be conquerors. For those who want their historical strategy absent any fantasy, it can be turned off on the launch menu just like a mod. 

"Sunset Invasion" will be available for download from November 15 for $4.99. I'll be kicking some Mesoamerican arse with my reconstructed Roman Empire the moment it goes live, I can assure you.