The aliens came here for one thing.... Females.
Humans believed they were the only intelligent life to exist... that it was impossible for another species to evolve in a way where they could prevail in something as great as space travel.
humans believed they were supposed to be the most technologically advanced species and the alpha predators...
They were wrong.
The Xandisians evolved in ways humans never could have imagined, they are natural-born killers with phenomenal strength and agility. their kind never went through the same devolution as humans, they never lost their natural instincts to hunt, kill, or breed. in a sense, the xandisian race grew not only more intelligent over time they also grew in strength becoming a species of warriors to be feared and respected. With their limitless potential and monstrous strength, they faced few threats and could survive almost any threat that befall their species, almost.
After an incurable sickness washes over the planet of xanadis, the majority of the female, young and elderly, and vulnerable population is all but wiped out, leaving a small portion of the male population to face the threat of extinction.
with no choice but to look to the stars for a means to save their kind from complete annihilation, the xandisians set out to find a race compatible with their own. after many years and countless failed expeditions, they finally find a species that matches their base DNA on a planet called Earth.
The only issue now is how humans will react.