Seishiro and Fuuma

If you have read X/1999 or Tokyo Babylon... You already knew Seishiro and Fuuma!
Like Elda and Freya, they also appeared in Tsubasa : Reservoir Chronicle (Because CLAMP reuse all their works characters and made them appear in Tsubasa).
In X/1999, Seishiro and Fuuma have no blood relation, they only Seven Angels fellow. In Tsubasa, they have blood relation. They are hunters, but Seishiro hunting the vampire twins, Kamui and Subaru. Fuuma is different.
Goodbye!