"High School DxD" episode 13 is part of the anime series based on the light novel series written by Ichiei Ishibumi and illustrated by Shiina Meguro. This particular episode aired as part of the second season, which is known as "High School DxD: New."

In this episode, several key events typically occur:

1. The story continues to develop the conflict between the main characters and their opponents.

2. There's usually more character development and exploration of the supernatural world in which the story takes place.

3. Battles between characters with supernatural powers are common.

4. Relationships among the characters may be further explored or complicated.

Without access to the specific content of this episode, I can't provide detailed plot points. However, if you're looking for more information about this particular episode, I'd recommend checking official sources like the anime's official website, streaming platforms where the series is available, or reliable fan sites that summarize episodes.

If you have any specific questions about the series or general information you'd like, I'd be happy to help with those.