Yamata no Orochi

Yamata no Orochi is an Evil Dragon known as the Venom Blood Dragon and a member of Qlippoth.

Appearance
Although Yamata no Orochi was not given a physical form upon his revival unlike the other legendary Evil Dragons, he has shown the appearance of an eight-headed Dragon with blood oozing from his mouth filled with sharp fangs.

History
Yamata no Orochi was killed by the Shinto storm-god Susanoo but his soul was later recovered and split into two sometime before Volume 18.

One half of his soul was sealed inside the holy sword Kusanagi Sword and the other half was given to Walburga for her use.

The Legend of Oppai Dragon and his Lively Companions
During the fight of Masaomi Yaegeki against Issei and the others in Volume 18, it was revealed that Yamata no Orochi's soul was sealed inside the the Kusanagi Sword and was used to help repair the holy sword. Even with just a scratch from Yamata no Orochi's fang, it was able to put Touji Shidou's life in danger with its venom. Masaomi and Yamata no Orochi was defeated with the combined efforts of Issei, Irina, and Xenovia. Ddraig noted that Yamata no Orochi's soul disappeared probably because of the ability of Irina's sword Hauteclere.

Yamata no Orochi appeared in Volume 19 but this time as a part of Walburga's Balance Breaker. He took his normal appearance but is impaled in a cross and entirely made out of purple holy flames. Even with just half of his soul used, he showed immense power as he was able to survive multiple attacks from D×D although they were able to still defeat him.

Trivia

 * Yamata no Orochi being sealed inside the Kusanagi Sword is ironic as the sword was found from his corpse.