The Black Reaper (Kuro no Shinigami) from [Darker Than Black Anime]

Hei (黒（ヘイ), Hei), also known as the Black Reaper (黒の死神, Kuro no Shinigami) or BK-201, is a human who gained Contractor powers. Hei is a young man of slender build with black hair and dark blue eyes. When in his Li Shengshun persona, he wears the casual attire of an exchange student. When operating as a Contractor, Hei dons a bullet-proof trench coat and a white pierrot-inspired mask that fully conceals his face.

Expert Hand-to-Hand Combatant: Hei is obviously extremely skilled in martial arts and is an accomplished acrobat easily able to do backflips and mid-air cartwheels with little effort in terms of physical strain. Hei's natural abilities are so impressive that even without his contractor powers Hei is easily able to take on other contractors. A combination of these physical attributes coupled with what appears to be the most powerful contractor power as well as a lack of obeisance arguably makes Hei the strongest character in the series.

[Special Ability]

Molecular/Electricity Manipulation: Hei possesses the ability to generate and discharge electricity through conductive media (i.e. he cannot discharge it through air or concrete) at sufficiently high amounts to kill grown men or short out a building's electrical systems. The power is more than simple electric shocks, as he can alter matter on the quantum level. He has shown the ability to transform integral particles on the quantum level.

Anime[myanimelist.net]
Character Info[darkerthanblack.wikia.com]
More Character Info[www.anime-planet.com]