Sajin
Komamura

Sajin Komamura captained the 7th Division while hiding his own face. He is an anthropomorphic wolf from a clan the Soul Society treated as beasts, and for years he wore a helmet and gloves so nobody would see what he was. Genryūsai Yamamoto gave him a captaincy without ever asking him to remove it, and Komamura's loyalty to the old man is close to absolute because of it.

Kaname Tōsen was the other reason he stopped hiding. Tōsen was blind, had never seen his face, and befriended him without knowing there was anything to overlook. When Tōsen left with Aizen, Komamura removed the helmet and went after him anyway, and he kept trying to talk him back long past the point where anyone else would have swung.

His Bankai, Kokujō Tengen Myō'ō, summons an enormous armoured giant that mirrors his own movements, and it comes with a cost the series makes literal: damage to the giant lands on Komamura's body. In the Wandenreich war his Bankai is stolen along with everyone else's, and he takes it back by using a clan technique that trades his humanity for a form nothing can kill. It works. He wins, and afterwards he lives out his life as an ordinary wolf, unable to speak.