Fei

Fei was a Chinese Ghoul associated with the gang Chi She Lian.

After their death, Fei's kagune was used to create the Quinque Douhi.

Past
During Kousuke Houji's time serving in China, he took part in an operation to destroy the gang Chi She Lian. Among the members killed was Fei, an associate of Tatara -- the Ghoul that would become Aogiri Tree's second-in-command.

Houji would use the Quinque made from Fei for some time, before passing it along to his junior partner, Seidou Takizawa.

Anteiku Raid
During the Owl Suppression Operation, Takizawa and Tatara came face to face. When he used his Quinque to defend himself and a wounded Koutarou Amon, Tatara recognized it as Fei's kagune. Enraged, he took revenge on Houji's subordinate.

Powers and Abilities
Fei was an Ukaku Ghoul, and a Quinque of average strength was produced from their kagune. Nothing more is known about their abilities.

Tatara
The exact nature of their relationship remains unknown, though Tatara became enraged at the sight of Douhi.