Yuuki Terumi/Biography

Terumi's "birth" was when the Susano'o Unit gained a soul. Over time, Terumi grew sick of being shackled to the endless cycle of destruction and creation that he shared with the Amaterasu Unit. He allowed the Susano'o Unit to be found by humanity and separated his soul from the unit, inhabiting the body of a young man with green hair. He contacted Relius Clover and Shuichiro Ayatsuki with the promise of creating a perfect Prime Field Device - it went haywire and a Black Beast was created, starting the Dark War. At some point, he became acquainted with Clavis Alucard and Valkenhayn R. Hellsing.

Phase Shift 1, Phase Shift 2, Phase Shift 3, Phase Shift 4
Terumi lost his body as the Black Beast arose, and demanded to Relius to create him a body. Before the scientist was swallowed by the Beast, he told Terumi that a vessel was inside the Magister's City of Ishana waiting for him. Terumi managed to penetrate its barrier, creating a body for himself through self-Observation.

In time, Terumi found the vessel, Kazuma Kval, and waited in his dorm for the teenager to wake from his sleep. When Kazuma awoke, Terumi introduced himself and asked if he wanted the Azure. He mysteriously left without much explanation on what the Azure is.

Watching as Kazuma interacted with Trinity Glassfille in the Great Library, Terumi mocked Kazuma afterwards and began to walk back to the boy's dorms with him. He openly mocked Trinity and told Kazuma to not get corrupted into becoming a mage. Terumi told Kazuma that he had to get the Azure by himself and they entered a park. There, Kazuma was assaulted by three half-beastkin, but Terumi nonchalantly sat on a bench and crossed his legs, applauding whenever the student dodged an attack. Instead of helping him, Terumi teased Kazuma until the student promised that he would find the Azure.

Rising from his sitting position and grabbing a nearby throwing knife that one of the half-beastkin had lodged in a tree, Terumi smiled. He ran towards the assailants and countered every attack they threw at him, repelling the group. As they retreated, Terumi threw the daggers on the floor, uninterested in them. He separated with Kazuma outside of the boy's dorms and looked over his shoulder, seeing Tomonori in the distance. Later that evening, Terumi entered Kazuma's dorm and warned him that Trinity was monitoring him.

The following day, Terumi watched as Kazuma was in a cafe with Nine, Trinity, and Celica A. Mercury. Catching the boy's attention, Terumi jerked his chin and walked onwards - Kazuma ran out of the cafe after him, finding the man near the edge of Ishana. He pointed out a hole in the Ishanan barrier, telling Kazuma that with this he could distract the Ten Sages. As soon as Trinity and Nine appeared, Terumi disappeared.

Kazuma had made it to the center of the Ishanan Cathedral, the Lost Gate. He taunted Kazuma deeper and deeper and asked him to put his hands on the cauldron beneath. Kazuma's memories came flooding back to him, and Terumi physically appeared - Terumi spoke, telling Kazuma more about his origins as a vessel, and the pair's shadows stretched to meet one another. As they began to fuse, they turned to see Tomonori staring at them.

Terumi watched as Kazuma battled against Tomonori and as the beastkin drew the Hihiirokane to fight them both. Together, the duo summoned a version of the Geminus Anguium: Ouroboros - Tomonori lost and was viciously killed by Kazuma while Terumi laughed and applauded. A brief while passed and their fusion had become complete, although both were exhausted from the fight. Turning around, they were found by Valkenhayn, who knocked them unconscious and dragged them to the Alucard Castle. They were locked behind several sorcery barriers and shackled with binding chains by Clavis. Months passed and Terumi and Kazuma had become mirror images of one another in their isolation.

After the death of Clavis, Nine, Jubei, and Valkenhayn entered the prison. Nine interrogated Terumi, who wildly laughed at her, but fell silent when she used Mind Eater on him, turning the God into her slave.

Ikaruga Civil War
When the war loomed towards its apex, Terumi saw Iron Tager entering the area where the Prime Field Devices had been kept.

Variable Heart
Lurking in the back of Hazama's mind, Terumi watched as he interacted with Meifang Lapislazuli, the Colonel of the Wings of Justice division of the NOL. Upon being assaulted, Terumi's spirit form lept forth from Hazama's body and began to strangle the Colonel, threatening to cut her to pieces and feed her to pigs should she continue act proudly. Both Terumi and Hazama soon left afterwards. In the 11th Hierarchical City of Shinatsu, Terumi, in his spirit form, was asked by Meifang near its cauldron to help her turn into a Nox Nyctores. He agreed to help, noting that she had nearly died. Terumi ordered her begin hating everything; the world; and herself. The plan ultimately failed, and Terumi returned to Hazama and Phantom.

Calamity Trigger
December, 2199 had come again for Terumi, but he, Hazama, and Relius had resolved to end the looping of time. Thanks to Hazama's manipulation, Noel Vermillion saved Ragna from falling into the cauldron within the 13th Hierarchical City of Kagutsuchi alongside Nu-13. Terumi briefly took as the front of Hazama's body, and he demanded that Noel recognize him and his existence as she had become the new Eye of the Azure. The plan was a success - the time loops had ended and Terumi's existence was Observed. He threw Ouroboros towards Ragna, only for Tager to suddenly appear and block the attack. Having decided he had already had enough success, Terumi left.

Arcade Mode
"Once one of the Six Heroes who defeated the Black Beast, as well as the one who plunged Ragna into despair, he may seem impulsive and shallow-sighted, but is actually quite crafty and clear-minded. Cold and cruel, he truly enjoys "despair" and "destruction" from the bottom of his heart, and starts the Imperator's even worse "banquet of madness.""

Central Fiction
"Once one of the Six Heroes who defeated the Black Beast. When he saw the transformed world, he muttered "Gotta redo it again?" and began to act in order to bring about the same history as before. His goal is twofold: to destroy the Master Unit, and to obtain a weapon of his own...."

Terumi barely survived his encounter with Hakumen. The body Trinity made for him died, but he was able to survive through crudely Observing himself, although this method would only keep him sustained for a week at most. He began searching for another vessel.

He found Hazama, explained what had happened, and through him, ordered that Noel go to the Kaka Village to deal with Ragna. He stayed with Hazama, barely being able to possess him, and watched as Nu battled against both Ragna and Noel. Not long afterwards, he was transported to Ikaruga, and told by Nine that he could obtain the Azure by killing Izanami. Although Hazama had told him that he would search for the Azure himself so they could fuse, Terumi began to search for a different vessel to fuse with, finding that he had outgrown him. Hazama had fulfilled his side of the deal, however, and had gained an Azure piece from Izanami – he told Terumi he wanted to fuse, but to be in control, and he complied.

Going to the Alucard Castle, Terumi pried open Clavis’ coffin after battling through the Prototype Absolute Defence: Blade of Reflections, which created a perfect copy of himself to fight. Winning, he took the Hihiirokane within, and used to separate himself permanently from Hazama when his former vessel tried to consume him. Terumi then absorbed the weapon into himself and left Hazama to his own devices. He drove Nu insane after she was defeated by Ragna, forcing her to fight Hakumen. While the knight was distracted, Terumi launched Hihiirokane at him, shattering his soul and taking over the Susano'o Unit, finally becoming Susano'o once more. He snatched Noel and Amaterasu, forcing them outside of the Embryo.

Terumi exited and returned to the unit frequently, being able to now summon it at will. At the gate with Noel in his grasp, Terumi battled against Es, the protector using the Susano'o Unit to do so. Amaterasu had Observed his victory before the battle even began. Soon Ragna and Jin arrived, and through their combined efforts, sent Terumi out of the Susano'o Unit. He was sent inside the Gate with Ragna by Noel, coming to the Azure Horizon. He fought his nemesis for the True Azure, and lost, finally dying after having cheated death countless times.