Biometal is a strange substance which can only be found in irradiated moonrocks.
On moons within a certain distance from the sun, moonrocks suitable for refinery are harvested. In every ten tons of crushed moonrock, there is about 1-2g of a strange material known as Prototon. After refining it into a liquid state, the Prototon is known as Biometal. It must be stored at 0 degrees Celsius at all times or it will activate.
Biometal is extremely dangerous. It is a parasitic, non-living substance. If attatched to a body, it coats it in self-replicating cells. It then takes over the body. However, it can only do this to substances with an electrical current (computers, robots), and as such things like de-activated robots and doors are immune to control. However, it can still coat the object.
Some warriors decide to coat their bodies in Biometal. This is extremely risky. Whilst Biometal is extremely dangerous and can kill the warrior, If the warrior can form a mental link with it, they can enjoy a symbiotic relationship with the Biometal body. This is extremely useful: Biometal bodies can withstand extreme heat, energy, can change their appearances, assimilate technology and turn into a liquid-like form to avoid things like missiles, rockets, blades etc. In addition, the link between the two lifeforms gives the new being incredible reflexes.
Someone with a Biometal body is a considerable threat. Being nearly immune to many conventional weapons, such as solid blades, energy weapons and rockets, there are few things that can harm them, let alone kill them. However, they have one major weakness: sonic attacks. This can cause the Biometal body to lose abilities temporarily, or in severe cases, die.
Kakamu is the only known being with a biometal body.