BG9 is a member of the Wandenreich's Sternritter with the letter 'K'.
BG9 has a mask like visage with four slots in it, giving it the appearance of a helmet. He wears the standard Sternritter hooded cloak. Beneath it however, his body is covered in mechanical coverings concealing various weaponry. His body also houses a multitude of tendrils. Beneath his helmet, a single eye glows. BG9 is a very tall individual.
BG9 is cold and calculating, speaking in an autonomous way. He is very direct, and factual, often using statistics when he speaks. Overall he comes across as robotic, even confessing to have never breathed. He is not above hurting children to get what he wants. Despite this, he does show some human traits. For instance, he appears to be quite sadistic, when he comments that it is a shame he won't able to use Soi Fon's stolen Bankai against her. Not only this, but he also begs for his life when Yhwach orders him to be judged.
Plot - The Thousand Year Blood War Arc
BG9 is a part of the initial invasion force that attacks Seireitei. He immediately faces off with Soi Fon, stealing her Bankai from her the instant she uses it.
Later, when Uryu Ishida is announced to be the successor of the Wandenreich, BG9 is shocked by the revelation. He then discusses the event with Bazz-B, Cang Du and Mask de Masculine, stating that is someone is to give an explanation, then it would be Yhwach.
When the Wandenreich invade Soul Society for a second time, BG9 immediately heads for the 2nd Division. He confronts Marechiyo Omaeda on the whereabouts of Soi Fon,claiming that despite doing an extensive search of the area, he has been unable to find her. BG9 attacks Omaeda, continually asking him where she is, despite Omaeda telling him he doesn't know. Eventually, BG9 attacks Omaeda's younger sister, Mareyo. Enraged, Omaeda attacks BG9. BG9 proceeds to impale Omaeda with multiple tendrils before unleashing a massive minigun from beneath his cloak. He fires it at Omaeda, only for the end to be destroyed.
Turning round, BG9 notes that his sensors were unable to detect Soi Fon's arrival. He then wonders why she is using the Shunko, as hers should be incomplete. Soi Fon then reveals it to be completed and called Eternal Shunko before attacking him with it. BG9 is hit and sent flying into a building. However, he quickly emerges from the smoke, still standing despite a small crack in his helmet, his sole eye now gleaming. BG9 attacks her with one of his tendrils, but Soi Fon grabs it and flings him from the rubble, smashing him into another building. BG9 stands up unharmed, his body revealed. Soi Fon questions how he can still be alive and BG9 states that he has never breathed.
BG9 then states that he was able to analyse Soi Fon's Eternal Shunko and it provided him with extraordinary data. He then opens his arms and compartments on his chest open up, revealing missiles which he fires at the captain. Although she escapes with slightly injuries, BG9 impales her through the wrist before catching up to her, reiterating again that he received some extraordinary data. His eye glows as he detonates a massive explosion in the air.
BG9 sets up a wall around himself as he analyses Soi Fon's body. Questioning why Omaeda would continue to resist as he rescues his captain, BG9 states he merely wanted to collect data on her before she died. BG9, now unable to hear them after his audio receptors were damaged in the explosion, is unaware that Soi Fon has just received one of Urahara's Shineyaku pills. As she takes it, BG9's body is impaired and he finds himself unable to move as well as before. Shocked at the fact that Soi Fon's Bankai has returned to her, BG9 braces himself as she fires it, scoring a direct hit. BG9
emerges from the smoke with a large portion of his face destroyed. BG9 later uses his Quincy: Vollständig to resurrect himself and returns to Silbern where he is to be judged by Jugram Haschwalth alongside Cang Du. BG9 pleads for his life, stating the two of them can still fight thanks to their resurrections. BG9 watches powerless however as Cang is cut down beside him.
Powers and Abilities
Tendrils - BG9 has the ability to wield a vast number of tendrils that he conceals within his chest. They are strong enough to impale a captain level fighter.
Minigun - BG9 summons a giant minigun with the Wandenreich symbol on it.
Missiles - From beneath the compartments on his body, BG9 can fire an array of missiles that cause enormous explosions.
Quincy: Vollständig - BG9's Vollständig is strong enough to resurrect him from potentially life-threatening injuries.