Brook

Brook is a male awakened and no 6 Vanguard. He has dark hair and ebony colored eyes. He is usually silent, taking in his surroundings and thinking, rarely speaking. He is usually very focused on his missions and ignores his companion, Nixie's, complaining and flirts. He is very logical but has an emotional side as well. He fights with daggers, both throwing them and holding them to fight but is afraid of water since he can't swim. He has a very keen nose which he can use to determine the history and background of a person or object. He loves virgins, obsessing about it when he eats and when he recruits, similar to unicorn lore, in which unicorns prefer virgins. His Y.I.D. is a horse of sorts, although more accurately, a unicorn, although no such horse exists with a horn on its forehead.

Brook is partnered with Nixie, vanguard no 9. She constantly makes romantic advances to him and he turns them down coldly, never fazing Nixie who continues to try to hook him. Brook appears to not be interested in romance at all, which is why Nixie's advances never work. Nixie typically causes trouble or doesn't follow orders well, leaving Brook to be the leader of their team.

Brook's awakened form is a unicorn with a rider on the back. The rider can elongate its arms and fingers and the horse body can spin, shoot out, and replace its horn indefinitely, making it a dangerous weapon which easily pierces through metal armor. His nose houses two eyes, similar to his ability to "see" into one's past by smelling his/her scent.

Brook's first seen mission was in the prison at Purge to conduct a Vanguard tears test. He entered secretly, killing a guard and taking his uniform. Later, in the prison, he stabbed guards with knives coated in Vanguard tears, turning them into feeders. He also stabbed a yoma, converting it into a yoma berserker, noting that it was very effective as a battering ram but stupid. He mercy killed a woman, knowing that she was pregnant and would probably die a horrible death, instead, giving her a peaceful death by snapping her neck. He later fought against Lucia, parrying her claymore with his knives but easily defeated her with a chop to the neck since she was only aiming for his legs to force him to kneel. Brook met up with Nixie, realizing that they were locked inside the prison. He burst out in his awakened form, killed all the armored guards, and then ate Ducard, calling him a delicacy for being a virgin. He tried to bring Lucia to Messire but was stopped by Victoria who used sensory control on him, causing him to trip and loose focus. He abandoned Lucia to run as Messire accepted failure and the town was waking up and would have spotted him. Under Nixie's command, he jumped into a lake and escaped. In his mission report with Nixie, he included a description of Grace and stated that he was influenced by an eye flying at high altitudes. He then went with Nixie to train with Messire.

Brook later tested out the tears of fear, having Nixie hand it out to the Apex during a meeting between the four apex branches. He talks about his deal with the apex over exchanging eris for gold, throwing knives at the bottles of the drunkards who dared call eris a whore or a witch. He later left when Angel attacked to see the effect of the tears. After seeing Eliah kill the corrupt beings and talk about finding her "big sister", he retreated, terrified, saying that the fourth eternal one was worse than Nina had described.

He was later seen at the vanguard meeting, discussing recent developments. He appears to be helping Baroness Van Lachery recuperate, having performed surgery to replace her missing eye and arm.