Kirin

A white-haired, pickle-loving hermit who is easily bored and lived on the outskirts of Entotsu City, famed for his knowledge about O-Parts (and repairing them) and his genius as a swordsman. His brother Kujaku claimed that no one has ever been able to wound him in battle. Despite his genius, he is not an OPT. A former Stea officer, he is now accompanied by his dog Jajamaru. After Jio, Ruby, and Ball departed from Entotsu City, Kirin decided to travel along with the three, because he wanted something to do. Kirin has been revealed to be the son of a Cyclops father and OPT mother, and is in fact the son of the younger brother of Mei's grandfather (see chapters 27 & 55). Kirin, unlike his younger brother Kujaku, has the Cyclops third eye on his forehead, which was open when he was born, and is very rare, if not completely unheard of[2]. His weapon is a katana. It is widely believed by fans that he may be the Arcaido spirit in a new form due to his extensive knowledge about O-Parts and the fact that he his half human and half cyclops. As a child he was trained by his father to be a swordsman along with his brother. Every day when his brother and he would spar, he would beat his brother until the day that his brother beat him after obtaining the power of the Adramelech demon, where he walked in shortly after his brother had killed their father. Still as a child, he attempted to stab his third cyclops-eye, in an attempt to be normal, and stop his brother's hate to him and his father, as the third eye couldn't be destroyed, he cut his left eye, blinding it, and leaving him with just two working eyes: his right eye and his cyclops eye.