The richest crime lord of England, and father of the twins Yue and Yui. Jeff commands a very dangerous British Firm (UK's organised crime group) and is feared by everyone for his sadistic personality and cruel actions. The reason of all this evil is very deep. Jeff was the youngest son of an ancient british aristocrat named Connor Hamilton, who already had three children before him: Joshua, the oldest son and heir to the family's fortune; and the twin daughters, Clair and Chloe. In his childhood, Jeff felt despised by everyone in the family, as most of the time, he was often excluded from most important events. At the age of 14, Jeff met a group of gangsters who were tasting the then new drug called 'Kinectia'. One of these gangsters offered Jeff a pill of this drug for a little ammount of money, and knowing he had nothing to lose, Jeff immediately took the pill, and instantly, his hands are on fire. It was then concluded that he gained the ability of pyrokinesis through the pill he took, and he also concluded that he can do anything with such power in his hands, and with this power, he killed his parents and siblings, took all the family's fortune for himself and burned the mansion with his family's corpses inside. Then he joined the group of those gangsters he met, and in so little time, he got to be feared by those who stood in his way, even other gangsters, thus becoming leader of this group which was turned into a mafia. At the age of 31, Jeff had been chosen as the groom for a forced marriage organized by the Thompsons, but instead of uniting two rich families, he took all the Thompsons' fortune for himself and executed the couple. As for their daughter, Lisa, she was spared by Jeff because he wanted an heir to take care of his business. 6 years later, Jeff and Lisa divorced as she couldn't stand his abuses anymore, but Jeff took Yue to him while Yui remained with Lisa. As the future inheritor of the Hamilton family's fortune, Yue lived with his father for years, but Jeff abused his son psychologically and physically in order to make him the perfect leader of his mafia, which went wrong, because at the age of 12, Yue ran away from Jeff's mansion, as he couldn't stand the abuses commited by his father anymore. The burn in his face, which made him lose a piece of his left ear and the vision from his left eye, is the result of so much Kinectia he consumed with time, although his flames got hotter and hotter.