The Calamity From the Skies

In Roswell, June 1947, a large object reportedly crash landed in Roswell, New Mexico.

Its arrival was hidden as well as its nature. Reportedly, it was an alien capsule. Its existence was blacked out, as well as all research and tests.

In 1985, the object was moved from is location in Area 51, Nevada, to a secure testing facility in the city of Acaridae, in Ivalicia.
The scientists there took a bold move that their counterparts in Nevada had never dared to do: gave the alien a name.

They called it 'Jenova'.

The testing on animals already completed, Jenova's cells were allocated to human testing.
In 1990, a virus was created from Jenova's cells. It was called the 'C-Virus'.

Depending on the individual, the virus had different effects. Many were horribly disfigured, transformed into monsters or living corpses.
Others had no effect whatsoever.

Reportedly also occuring in 1990 was the use of Jenova's cells to create 'replicas' of living human beings with the potential to carry and use Jenova effectively.

Very few people with the ability to carry Jenova resulted in this. The only way for the others to become 'whole' was for the blood of who they were cloned from to be infected with Jenova and then injected into them.
Until such a time that they are injected with this, the 'replicas' that resulted from the cloning are referenced as 'Genomes'.

From all accounts, there is a human being able to produce offspring that are 99% likely to be able to carry Jenova. He worked on the Jenova project and transferred to Acaridae with it, originally being a scientist for it in Nevada.
His two children were the ones used for the 'Genomes'.

Though the identities of them are unknown, it is confirmed that they do not share the same mother. His first child was, in fact, infected with Jenova cells through his mother while in the womb.

The other also carries Jenova cells, though was infected during adolescence.

Initially, it was believed he did not hold the potential to carry Jenova. According to a report from 2004, he was apparently spliced with the DNA of the first brother. This may have affected his ability to carry Jenova, or simply activated it.

The first brother is reportedly dead. The second's location is unknown.

There are several others capable of carrying Jenova. They are not properly documented.