The Voiders

Some sort of wandering group faction. They are "bad" and seek to destroy the player and all other living creatures. Some say they are humans who got lost between the planets, spent too much time alone and went crazy. others say it is a sickness caused by nanobots in the blood stream that has turned them into blood seeking monsters.

They're very tribal looking, the ships are angular and brutal, they like to ram and rip everything apart.

"If they take the ship, they'll rape us to death, eat our flesh, and sew our skins into their clothing. And, if we're very, very lucky, they'll do it in that order.
-Zoë

yeah something like that but i thought it could be cool to make it so that there is actually something hosting itself in their bodies.

I like that idea. I wanted to have a faction inspired by Mad Max, like pirate but much stronger, with a more cohesive vertical structure, with their own mythology and extremist coderule, with no attach in the galaxy appart from their mythological home planet that nobody know where it is. They constantly move around the galaxy, ripping apart civilian and military alike. Your idea is very close to that, this will make for a perfect faction to add danger to random places in the galaxy.
We could have these nice guys actually inflicting themselves these host / nanobot / weird stuff as a rite of passage.
I like it a lot.