The Celescion:
They are an ancient alien race that came to earth to save it. After the wars were over, the Celescion took over a good portion of the planet, inhabiting it and building cities on top of the rubble to allow the human race and any other forms of life that came to the planet an escape from the aftermath of the bioweapons that engulfed much of the world.
Tyrakk:
Alien race that has come to seek sanctuary on earth due to a virus that broke out on their planet. They are mostly scavengers, and although not very violent, they can be very viscous if felt threatened.