[Fey]

If you're open to a small group as opposed to 1x1 I'd love to join in on this, it sounds like a lot of fun. I'm very flexible as a rper, I can go as literate as you want/need...though I'll be the first to admit I'm not good at paring down wordiness. I can give a try, though, presenting your idea more as a narrative:

All was peaceful on Earth, or as peaceful as a war-loving race could ever be. Secure in their advanced technologies they believed they could face all challenges that presented themselves as they stretched their presence into the unknown, space. But their explorations caught the interest of the [Alien sounding name here], and that's when they learned that technology isn't the only way to wage war. This new race wants the Earth's resources to add to their own, and they aren't asking politely.

Wielding Mana, magic, the aliens easily overpower the worlds military until it is discovered a small percentage of the population can do more. They can wield the left-over Mana from the alien attacks to defend their home world. But this brings them to the attentions of the invaders, and since it's their own powers they can easily track it back to the one using it. The risk is great, the price of failure even more so. This is the story of those willing to do what has to be done to save the World.

Hopefully that's sort of what you were thinking, if not please to be ignoring ;)