Genesis Rhapsodos (ジェネシス ・ラプソードス, Jeneshisu Rapusōdosu), also known as G, is a character in Crisis Core -Final Fantasy VII- and Dirge of Cerberus -Final Fantasy VII-. He is a 1st Class SOLDIER born from the Jenova Project, and is initially believed by Sephiroth to be the namesake for "Project G" in the Jenova Project. Initially a loyal SOLDIER member who wishes to prove himself a hero like Sephiroth, Genesis begins to suffer from genetic Degradation due to his imperfect infusion of Jenova's cells, and leads a rebellion against Shinra with the intent to find a cure.
In the Japanese versions of Dirge of Cerberus and Crisis Core, Genesis is voiced by Camui Gackt. In the English version of Dirge of Cerberus, he is voiced by Robin Atkin-Downes, which has been heavily criticised. However, in the English version of Crisis Core, Downes's heavily accented rendition of Genesis was replaced with a younger-sounding and faintly-accented Genesis provided by Oliver Quinn, whose performance has been better received.
(will add in more once I read more in depth)