Hazel Grouse is a character in Saiyuki Reload who first appears in the "Even a Worm" arc. He hails from the affluent Western continent and crossed an ocean to visit Togenkyo. Dressed in clerical attire, he follows in the footsteps of his adoptive father and master, exterminating demons. His master was killed by demons when Hazel was young, fueling his relentless desire for revenge and hatred towards them. He learned about Togenkyo from Ukoku, whom he met previously, and knowing it was ruled by youkai, traveled there with his bodyguard Gat to eradicate all youkai.
Hazel possesses a unique revival technique that allows him to exchange souls. He uses the souls of defeated youkai to revive humans who died from youkai-inflicted wounds. The origin of this ability remains unknown, and he has lost part of his childhood memories.
He is a strikingly handsome young man with silver hair, blue eyes, and a neutral expression. Speaking with the distinct intonation of the Western continent, he initially comes across as elegant and gentle but is actually quite confident and often provokes others. In reality, he is highly intelligent and physically capable. While affectionate towards Sanzo, he shares a contentious relationship with the other three youkai, particularly Hakkai.
In the anime adaptation, Saiyuki Reload Gunlock, Hazel's backstory differs. He frequently killed youkai and was eventually turned into one himself as punishment, leading him to kill the priest who raised him. After continuing his demon-slaying spree, he was ultimately killed by Gat on orders from the Great Spirit. However, Gat revives Hazel using his own life energy, giving Hazel's mirror the power to revive dead humans with youkai souls (in the anime, the mirror seems to hold an infinite number of souls). Hazel's memories are altered to believe he revived Gat instead.
In the series finale, Hazel attempts to kill Sanzo and revive him to enlist his help in eradicating all demons. Gojou, Hakkai, and Goku intervene, and Gat is fatally injured in the ensuing battle. Before dying, Gat reveals the truth to Hazel, restoring his original memories. Hazel is then defeated in his youkai form by the Sanzo party and, feeling his life was wasted, asks Sanzo to kill him. Sanzo complies but comforts Hazel by saying that no life is ever wasted before fulfilling his request.
