Konosuba: God's Blessing on This Wonderful World!, Vol. 17 (Manga): Volume 17 - Natsume Akatsuki

Even after confronting the lady from the bath--or rather, the evil god Wolbach--Megumin still feels like something isn't quite right. It seems like Megumin has crossed paths with Wolbach before, and when Kazuma tries to ask about it, he realizes he's made a grave mistake...