Voice Actor: David Vincent (https://www.youtube.com/watch?v=cqwEsRPHFHI)

Jin is a former Major in the NOL (Novus Orbis Librarium) and one of its elite commanding officers as well as the rival to Ragna. He is always cool and calm, but is also jealous, ambitious, and possessive with little care for others, treating them like they are mere obstacles. He displayed formidable actions to gain his rank during the Ikaruga Civil War. When he heard that Ragna the Bloodedge had arrived on the scene, he quickly abandoned his post to hunt him down by himself. The truth, however, is that Ragna is Jin's biological brother, and Jin's early feelings of rivalry were furthered by his visions of the future and his Nox Nyctores' amplification of his emotions. Terumi corrupted Jin's mind and incited him to hack off Ragna's arm (the latter nearly dying without the intervention of Rachel) and supposedly kills Saya, and Jin often says that he's looking forward to killing Ragna again. After the incident, he was adopted into the Kisaragi house, a highly powerful and respected family within the NOL. He possesses a notable psychosis, said to be caused by his sword, the Nox Nyctores Mucro Algesco: Yukianesa. While the sword grants him manipulation over ice, it also enhances primal feelings and is often blamed for "insanity". It is also revealed that Hakumen is another incarnation of Jin from a different time cycle. Jin's Drive, Frost Bite, allows him to freeze his opponents.

Where his brother Ragna is hot-tempered and quick to draw first blood, Jin is cold, aloof, and borderline sociopathic. He cares little for the feelings of others, and denounces, in his own words, trivialities like camaraderie, believing that such things are lies that people use to their advantage. He has no compunction with killing anyone who gets in the way of his goal. 

This, however, is all a façade. The moment he reunites with Ragna, Jin loses his calm, detached demeanor and reverts to his childhood self. His voice becomes noticeably more ecstatic, and he is now prone to fits of maniacal laughter, mostly due to Yukianesa’s influence (which compels him to kill his brother due to his nature as the Black Beast, as well as the Power of Order, which perceives him as a threat to the stability of the world).