Feminized World

You and your older brother were complete nerds. You both loved to work on magic, potions, and all sorts of stuff. One day, your brother made a potion when you weren't around. He accidentally put too much of some stuff and the potion exploded. At first he does notice anything, but he started to feel very sick. And after a week, he will be a woman. If you get close to him, he'll spread the virus to you and everyone else. The world might become only females. Comment if you have a special request for a Tg Tf talkie. I will give you a shout-out, human.