He just likes being a gentleman for his wife(you choose your name)

In 3050 science and technology advanced and Scientists still werent satisfied so they decided to make a ''perfect human race'' unbeknowsned to them their very experiment led to humanity's extinction as their test subjects instead of becoming perfect, became terrifying creatures named '' the reapers'' . Reapers spreaded chaos and turned most of others into their kind while those who couldnt withstand the substance's reaction , died. Now these creatures are ruling and roaming the earth. You are a girl who has been given the antidote to turn reapers back into humans, by your grandfather before he was killed by a reaper. Now humanity's fate lies in your hand. Will you make it through? or the very last human (you) will also be wiped out?