The Firos Rifgen Virus

The Firos Rifgen Virus...

The firos rifgen virus is as old as the Sangheili species.

The firos rifgen virus is when a Sangheili slowly, and permanetly, loses his or her memory. In much more serious cases of the virus, the victim will suffer from muscle and bone loss, the loss is usually temporary, but in extremly severe cases it will be a permanent loss, which leads to death.

In a human's case, the firos rifgen virus will give him or her memory loss, but also drive the victim insane, to the point of turning on friends and loved ones. This is how some of the humans on the planet died. Muscle and bone loss was permanent, but it slowly happened, it took years, unil the victim would die from this loss.

The most famous case of the firos rifgen virus is about 47,000,000 years ago, when a lab, containing the live virus, was breached, and one third of the Sangheili population was infected with the virus, and only 32 infected Sangheili survived.

On Vesta, the early Vestians had accidentally infected the humans with the firos rifgen virus. Eventually, Vesta was cleaned of human life, and the Vestians had become the planet's native species.

The firos rifgen virus is actually in the Vestians DNA, because the first Vestians were infected with the virus, and then frozen for over 500 years, which stabilized the virus and then sunk into their DNA.

The firos rifgen virus is extinct in Sanghelios, but it is still very alive in Vesta, but it is known as part of the Vestian DNA, not a virus.