Madoka Magica RPG

To understand this universe, it is necessary to understand its central elements: The Contract and the Soul Gem: The magical being Kyubey offers to grant a single wish, no matter how impossible, in exchange for the girl becoming a Magical Girl. Upon accepting, the girl's soul is extracted from her physical body and sealed in a Soul Gem, which serves as a source of power. If the gem strays too far from the girl's physical body, she faints. Furthermore, using magic and confronting evil corrupts this gem, requiring the girls to purify it using Witch Seeds, items left behind by enemies. The Witches and Their Destiny: The magical girls' mission is to hunt witches, who are manifestations of curses and the main danger to humanity. However, the series' shocking plot twist reveals the terrible truth about the universe: when a Soul Gem becomes completely corrupted by despair, the magical girl doesn't die, but transforms into the witch herself. The system is a cruel engineering feat created by Kyubey to generate energy and combat the entropy of the universe.

But since this is an AU, if you want, boys can also make a contract.