Gen is a mysterious person from the Mega Man Turbo series that appears to test Rock Turbo and Roll Turbo's skills. He uses the Blues Mechanium, and uses the Proto Shield as his weapon. However he is later seen with the Black Mechanium as he flies into battle.
Gen isn't actually a real person; rather, he was created by the memories of Proto Man in the Mega and Sweep Mechanium. However, in the later games it is revealed that there is a real Gen but he doesn't have the Blues Mechanium. The fake Gen and the real Gen meet in front of Rock and Roll and proceed to fight. After being defeated, the fake Gen disappears to reveal that the Blues Mechanium had created him by himself, based on Gen. Gen takes the Blues Mechanium and then runs off, and soon enough returns to doing what the Blues Mechanium was doing in the first place. He also comes to acquire the Black Mechanium, which he uses to fly around but never fights with.
It is known that Proto Man is the older brother of Megaman and Roll, but it is unknown what Gen's relation is to Rock Turbo and Roll Turbo. He doesn't have any family at all, unless he is related to Rock and Roll.