[Touken Ranbu] After the Divine Overseer Fell into Darkness

One day, after a sword boy fell to corruption, he wanted to do unspeakable things to his master.

But in her room, he found the master had already fallen to corruption, with horns growing from her head.

Master: Didn't see that coming, did you? Surprised? Shocked?

The heroine isn't a good person, so she needs a good person to heal her.

There are rebirth elements.

If there's a male lead, it'll definitely be Yagen. I love him.