Fujimoto is a priest at the Southern Cross Monastery, a Paladin in the True Cross Order (the title awarded to the strongest exorcist), Shura Kirigakure's mentor, and foster father to Rin and Yukio Okumura.

Abilities:
He was qualified as an Knight, Dragoon, Doctor, Aria and Tamer. He has a cait sith familiar, which he called Kuro.
Shiro is a man dedicated to his duties and was considered the strongest exorcist. Stealing the demon-slaying sword Kurikara, Shiro and Mephisto ultimately used the sword to seal the demon heart of the son of Satan and Yuri Egin. Shiro then adopted Yuri's children, Yukio who did not inherit Satan's power, and Rin, full inheritor of Satan's powers.

Source:Wikipedia