It's the 23rd Century and humanity had colonized most of the Solar System, at least we'd got most of the dwarf planets and Plutoids, along with some of the larger asteroids, and some in other systems. We'd even managed to develop a primitive FTL drive, fast enough to take us to Gliese 581 in about three months - as far out as we have colonies. And yet we'd yet to encounter any alien presence - not much, at least. Sure, there were the Dryads, but our relationship with them was (and is) much like that of Rome and China. We had even managed to terraform most of the worlds we colonized in a way that each one still had its own unique biosphere via the dryad technology of genetic scrambling. It was a time of peace. Life was good, the economy was good, 'twas all good.
And then these squid-faced bastards show up and fuck up everything.
They weren't really warriors, we knew that from the start. They, the Zarnikhs as they were called, were scientists, like the Dryads. They seemed harmless enough, but some of our higher-ups knew better. The first tip-off was their 'requests' for trade. They were asking a hell of a lot while offering so little. The UN smelled bullshit and declined their offer. They again made a request, a bit more forcefully, in a way that sounded almost like they were threatening us with military force. We again politely declined, a bit more forcefully, in a way that almost sounded like we were telling them to bring it. And holy hell did they ever bring it.
As we suspected, they weren't the best at war. At least any semblance to conventional war. We had thought of the idea of using genetic scrambling as a weapon, hell, the Scandinavians came up with it - but we all agreed that it wasn't worth the money, and we didn't have anyone we hated enough to use it on at the time. These bastards had turned genetic warfare into an art form. They had three main kinds of bombs that they really loved to use. The first kind was the standard genetic scrambler turned into a weapon that could be dropped from a starship or fired out of one. They'd drop them on the wilderness - theirs seemed to be geared more towards turning everything predatorial - and watch as they wroke havoc on the more rural areas. That's how they first targeted Gliese 581c. And that was just the beginning. They also had accelerator bombs, that (you guessed it) accelerated the evolution of whatever they hit. And just like the future is unpredictable, so was this thing. Some animals became docile little pet-things, others, well, when the whales on your planet turn into
Gaghiel, you know what to blame. The Zarnikhs fired these at wildernesses, too, but every once in a while it'll hit a human settlement and turn everyone into 'Freaks'. It's not pretty, and most die either by the mutations or suicide. Some get good mutations (like faster legs, stronger jaws, stronger arms, things like that, though they always look mutated), though that's pretty rare.
But by far the worst thing these assholes have come up with is the Atavistic Bomb. You ever want to get turned into an ape, or walk on all fours, or sprout a tail? Get hit by one of these things, it'll do that. They dropped these things on every city on every planet 15 lightyears out or more within the first week of the war, and suddenly each one turned into Planet of the Apes. Not literally, of course - even those directly hit didn't go further back than Sahelanthropus, physically or mentally - but it did enough damage to do its intended job, and that job was to screw our colonies to hell. And then they would send in their Warbeasts - Genetically altered monsters created by the Zarnikhs specifically for waging war. And they do their job flawlessly.
That war started four years ago, and they've been continuously hammering us ever since, with conventional warfare, gene bombs, and Warbeasts. Now all we have left are Alpha Centauri and the Sol system, officially. But we've started to do better, despite losing ground. We've still got no cure, but we've developed better power armor, better space weaponry, and better shielding systems (and tactics) to keep from getting effed up by those genetic bombs. More importantly, we've discovered a neat little quirk of those gene bombs. You see, if someone were to somehow get hit by an Atavistic and Accelerative bomb at the same time, it would do this neat thing to the brain I like to call 'turning you into a Jedi'. Well, it gives you some sort of psionic power, at least. These people, young and old, got scooped up by UN Skyfleet and put into special battalions, alongside certain Freaks that got lucky to go out and beat the shit out of the Zarnikhs, and pry their filthy little hands off our worlds, getting the more dangerous missions, because UN Skyfleet thinks they can handle it.
And y'all are just a few of them. In fact, you're the worst, the scummiest, the Dirty Dozenest, the most inglorious basterds the UN has yet found out of all the psionics on all the worlds, military or otherwise. And y'all are the best, because this could be the last chance you get before we throw you to the Zarks in a gift bag. But the United Nations Secretary General is a merciful god, and has decided to give you this second chance.
And you had best use it.