Cralkhi Symbiote

Raihosha and Caroline Carr are currently the only known possessors of this organism. Rai claims that he got it in a biowarfare attack in the Sigma Draconis system in one of the alternate universes he explored. Caroline became a carrier in June of 2017 after sustaining serious injuries.

From Raihosha's explanations, this organism was originally intended to wipe humanity off the face of the planet by an incredibly xenophobic race, colloquially known as "Kangas." Unfortunately for the Kangas, instead of being 100% effective, it was only 99.8% effective. The remaining 0.2% managed to develop a symbiotic relationship with the organism.

The benefits of this symbiosis is that the host gets about a 15% increase in reaction time and has an incredible resistance to disease and the effects of aging. Most virii and bacterial infections don't stand a chance. The effect of this is that unless the host is killed through malice or accident (and even then, the symbiote will act as an internal EMT to try and keep the host alive), their lifespan is unlimited. Actuarial studies tend to suggest an expected life span of 5-10,000 years before accidents do catch up.

The downside is that the host cannot give blood transfusions and must treat their blood as a potential biohazard, nor are males encouraged to have children with women not already hosts. This is due to the fact that the symbiote is still a bioweapon, and still lethal to 99.8% of humanity. It can be passed through blood contact and through genetic transfer, as in the fertilization of an egg. The resulting fetus will have a symbiote, and the mother will be attacked by the same symbiote unless she has one of her own to defend her body, or if she can accept a symbiote. In the case of a genetic transfer, even with the care available from Raihosha on Aescapulus, a mother only has a 20% chance of surviving pregnancy.