The Star Wars universe has a big variety of races/species in it. I don't think they have a hostile "take over your body" enemy there so let's see how they fare against those.
The adversary will randomly take over one of the Galactic Empire's planets and will attempt to spread to more planets. It is up to the Galactic Empire to completely eradicate them.
Round one: Xenomorphs (Alien)
Round two: Necromorphs (Dead Space)
Round three: The Flood (Halo)
Round four: Reapers (Mass Effect)
Round five: the Zerg (Starcraft)
Round six: The Borg (Star Trek)
Round seven: Tyranids (Warhammer 40k)