Demon Slayer: Magical Girl Guang

(No CP, the protagonist is an ordinary magical girl from Puella Magi Madoka Magica, with angst, and she lands right in the Mugen Train arc after transmigrating.)

As a magical girl, Xuecheng Guang was about to collect the Grief Seed before her when, just as her hand touched it, a flash of light appeared and she found herself in a forest. It was just like the transmigration her friend had told her about. Not far away lay an overturned, rather old-fashioned-looking train. Suspecting a witch was causing trouble, she went to investigate and ask where she was.