Xetra is an Alien race who seeks for a new planet to establish live on because the recourses on their home planet are almost gone. So unfortunately for the EUR (who already has their hands full on Theremo Corp) they picked the Earth because it has lots of recourses. In this stage of their invasion they mainly deploy from outer space.

Xetra uses almost none tech but hordes of aliens. The main units are weak but in big numbers they can be deadly but are easily defeated these units are mainly used for scouting purposes. The invasion troops are a total other story, Big strong bug like creeps who can smash trough tank armor. The brains behind the army??? Well no one ever survived a encounter with him.