Genesis is an original character in the Compilation of Final Fantasy VII, serving as the main antagonist of Crisis Core. A failed experiment by Shinra to infuse their soldiers with Jenova's cells, he was abandoned in order to make way for the more successful Sephiroth. Genesis is obsessed with a poem called LOVELESS, which he believes to be a prophecy he seeks to fulfill, using Zack, Sephiroth, and Angeal to further it. Genesis is selfish and bases his actions on self-preservation to the point of self-destruction.
This VC is just a little bit of a wash either way. Robin Atkin Downes' Genesis is the same vein as Paul Eiding's Hojo - awesome idea, dicey execution. Genesis as a character is controversial by sheer virtue of his existence in the series's pre-existing story, but a phenomenal VO performance could have really upped the ante, and Robin could have absolutely been the one to crush it. He's a charismatic actor, with a strong voice and a wide acting range and skillset. Unfortunately he only got a tiny cameo in Dirge of Cerberus, was recast afterwards, and they had him do a cheesy accent for some reason.
Oliver Quinn's performance is not really great. Crisis Core's VO direction is a little hit and miss. Zack and Sephiroth are utterly fantastic, Angeal is rough-edged but mostly okay, and Genesis is definitely questionable. He does lend him a certain "alien" air which I appreciate, and he certainly nails Genesis's immature and pretentious feeling, but his delivery is often pretty wooden. I suppose he fits better than Robin, but neither are really ideal as they are. Which hey, I guess is the story of Genesis.