Momoe Nagisa: My regret

Momoe Nagisa, once a Magical girl and often a Witch, is Madoka's second lieutenant as a bearer of the Law of cycles. Like Sayaka, she accepted this duty because she had one last regret, but what happened to her after Madoka took her in after her untimely death, before she decided to help save Homura? Started off as a short drabble, became something a little longer than planned...