High School DxD Novel Vol. 7 (novel)
After a perilous start to the semester, peace is finally returning to Kuou Academy. At least, until Odin, a god from the Norse pantheon, shows up. Dealing with the lecherous old man is tough enough on its own, but a sinister group is also plotting to kill him. Issei and his friends will have to pull out every trick they can manage to make it out of this one!