Aliens

The Aliens are faction from another part of space that one day appeared in Lactea. They are extremely violent and seemingly do not understand or actively resist human communication. They seem intent on destroying mankind. They are the secondary enemy faction.

Origins
There is no information on the location of the home world of the aliens. Humans have yet to understand their motivation for coming to Lactea and why they insist on exterminating humans. The only information known is that their appearance in Lactea is related to the activation of the Mechamon. The aliens are not uniform, and may possibly be made up of different races or species.

Crushing blow against the Confederacy
The Alien fleet is made up of ships that are part living alien matter and part mechanical matter. They also employ smaller, strictly living creatures to do battle, though it is assumed that the creatures are not the ones piloting the larger vessels. Their strength, speed, and sheer numbers allowed them to travel unmolested through Lactea during the days of the Confederacy. The Confederacy was highly ineffective against them in battle, and one of the Eight Colonies was lost to the Alien Horde. No one has been able to make contact with them since.

Rise of the Empire and defense against the Horde
Once the Empire had crushed the Confederacy, they turned their attention to the Alien fleet. While their Mechamon proved effective at defeating the enemy ships and creatures, the number of Alien forces seems to be ever increasing. The Empire's forces have kept them at bay since, but the areas where the Aliens have created strongholds known as Hives remain.

Lactea Conflict
With the Empire becoming invested in their war with the Free Colony League, the Aliens were given the opportunity to run wild yet again. Attacks on colonists and space ships increased, however The Protagonist was able to destroy multiple Hives during their journey, effectively reducing the number of Alien forces. Using data gathered by The Protagonist and the researcher Maple Leaf, the FCL was able to deduce that most of the Alien vessels could be captured, reprogrammed and piloted using a Mechadex. While many FCL officers and pilots rejected the idea, they soon found that the Alien vessels were quite easy to pilot and highly useful in combat.