This episode focuses on the backstory of and the introduction of Norse mythology. High School DxD: Queen (Rewrite) - Episode 3: First Day!
This episode is a pivotal moment for Issei Hyoudou as it introduces , a kind-hearted nun who becomes one of the series' most central characters.
Two agents from the Vatican, Xenovia Quarta and Irina Shidou (Issei's childhood friend), arrive at Kuoh Academy. They are on a mission to retrieve stolen Excalibur fragments.
Kiba spots a picture of a holy sword, which triggers a deep, vengeful trauma from his childhood involving the "Holy Sword Project".
A tense confrontation occurs between Kiba and the Church duo. Kiba’s speed proves ineffective against Xenovia’s power, highlighting the massive threat these "Holy Sword" users pose to Devils. Season 3 (BorN), Episode 3: " Cat and Dragon "