On Genesis 2 it is very very easy to get a reaper compared to the normal method. With your tek suit, fly to Rockwells innards and put lots of beds outside (or on unofficial put beds at the boss terminal in inside), and bait a reaper Queen into the acid beneath the boss terminal. Then hover above it while the queen slowly dies, then when it gets to about 8k health begin baiting it to the ramp part. Finally, once its on around 2k health it should be out of the acid, where you should keep running at it until it impregnates you!