Mimeosome

Mimeosomes, or "mims" for short, are the bodies of the humans of Xenoblade Chronicles X. While these bodies are human-like, they are mechanical in nature. However, they were designed to mimic human physiology in every way, aside from a few minor details like the ability to use Overdrive to boost their abilities in combat.

The bodies are all remote controlled from the Lifehold Core: if it fails, all mimeosomes will die.

Appearance
Mimeosomes resemble humans in almost every way, although their insides are metal rather than flesh. The blood that flows through a mimeosome is blue, hence the Japanese name "blue blood".

Since they are meant to be human, they still require things like water and food to survive. Additionally, they are still vulnerable to disease.

Because mimeosomes are essentially mechanical, it's possible for their appearance and voice to be changed without issue. Yardley owns a machine that can change a mimeosome's appearance, gender, and voice, although its existence is illegal.

It's also possible for people to switch mimeosomes, although that also requires equipment from the Lifehold Core.

History
When the humans fled Earth, they had no idea how long it would take for them to find a new planet to call home: it could take decades or centuries. As a result, the humans are stored in the Lifehold Core while the mimeosomes they've created live their lives as the humans within. Their goal is to retrieve the core and get their bodies back.

The bodies of the humans who fled Earth are all artificial mimeosome bodies, as Cross realizes when their left arm is severed in a fight against a Qmoeva during.

In, it is revealed that the Lifehold Core does not actually contain the human bodies in stasis, and that the data within had already been destroyed in the crash landing on Mira. As a result, it's still a mystery as to how the mimeosomes are still alive, whether the Lifehold Core was really necessary for mimeosome survival, and if the humans can get their organic bodies back.