[ WP ] An Alien Empire invades the Earth . But things go horribly wrong when they realize that of all species on the universe , Humans are the ones with the greatest affinity for war

`` L'kaike, charging!'' I shouted a warning, only seconds before the L'kaike warrior blew through the portcullis, a large kinetic pistol in one hand, and a long knife in the other. No matter how many times I had seen them fight, they always looked so strange. They seemed so ungainly with only two legs, and they seemed so limited with only two arms. Even their sensory organs were lacking, only two eyes and ears. In every way, they seemed primitive and backwards, like they should barely be able to stand. Every Nurn thought the same, until they saw a L'kaike in action. Their world's gravity was strong, nearly twice as strong Nurn Prime's, and that strength made them terrifying. On their world, we were slow and ungainly, and on other worlds, they were fast and strong, terrible in their might. 
 
 As the L'kaike burst into the bunker, my squad immediately opened fire, but the L'kaike was faster. It rolled sideways and raised it's large hand weapon, coughing like an angry Juhgt. Two coughs, and two of my warriors fell, large holes appearing in their abdomens. I aimed both sets of rifles at it, each set of eyes tracking the L'kaike separately, before firing. My first shot missed, as the L'kaike dodged impossibly fast, but my second caught it in the arm. The pulse round burned clean through, and the L'kaike gave a cry of pain, dropping its ranged weapon. Its good arm still held its wicked looking blade, and with a yell in their strange tongue, the L'kaike was upon me. Two of warriors leapt to my defense, the L'kaike bulled them aside, driving his knife into the thorax of one, while head-butting through the carapace of the other. As I readied another shot, it was on me, and my pulse rifles discharged as the charging beast slammed into me. My legs scrambled for purchase, before buckling under the weight of the L'kaike's body. 
 
 We went down in a tumble and I lost my grip on my rifles, all four arms knocked askew by the blow. Eventually I was able to get to my feet, each of my legs finally getting a grip. The L'kaike had been killed by my rounds, but its charge had cracked my thorax carapace, and I knew it would take weeks to grow it back strong again. One L'kaike had cost me four warriors, damn monsters. I heard more shouts, and as I gathered my rifles and looked out the bunker, I saw that this had been just a scout, their main force cresting the horizon. As I saw what had to be at least a thousand L'kaike and their armored tanks, I silently cursed whatever forerunner had decided to invade their Earth. 
 
 We learned at the Academy that we had attempted to uplift the L'kaike as warrior-servants, in an invasion designed to bring them to heel as attack kulhns for the Hegemony. However, this kulhn was more dangerous than we anticipated, and attempting to muzzle it had been our undoing. Reports indicated that they had thought themselves alone in the universe, and had we not attacked, would have likely ignored us. By attacking, we informed them that they were not alone, and their galaxy was a hostile one. Whereas once we thought ourselves masters of war, we found that the L'kaike truly thrived on it. It turned out their entire history did not have even a single year free of conflict between them. Tens of thousands of their solar cycles, and not even one of them was free of violence. How do you fight an enemy like that? With a history like that? We did n't know then, and honestly, did n't know now. 
 
 They recovered from our initial assault far more quickly than anticipated, and when they counter-attacked, we realized for the first time what we had awoken. Now they had some external threat, some common enemy shared by their whole race. They never stopped, no matter how grave their losses, and that's when we learned a more terrifying lesson. They did n't die. Their bodies healed nearly everything, given time. An energy round to their bodies was less effective than normal, as it cauterized their wounds and stopped them from losing internal fluid. Even when their limbs were ripped off, or they suffered catastrophic damage, they did n't go into shock and die. I had personally seen a L'kaike operate on itself, sealing an abdomen wound with some adhesive gel, before launching itself back into the fray. These L'kaike were monsters, and in our folly, we attacked their lair. 
 
 Worse than their physical strength, the L'kaike were cunning and intelligent. When they took prisoners, they dissected them, studied them, and learned from them. Neither our technology, nor our biology, were safe from their prying hands. Less than a year after the initial assault, they had developed their own primitive warp drive, and less than a year after that, they had driven us from their home system. Not content to simply defend their world, they had discovered a universe full of creatures to fight, and wars to win. They came for our other worlds then, and with each battle, they grew stronger, feeding on the carnage and blood like some demon of lore. Now, they were in the home system, on Nurn Secondus. 
 
 Shouting orders, I gathered my troops in a defensive line, with every cannon and plasma gun aimed. As soon as they entered our range, we opened fire. The war for our system had begun in earnest now, and the L'kaike attacked like the kulhn we wanted them to be.
