The Valentine Brothers are characters in Team Four Star's abridged series Hellsing Ultimate Abridged. A pair of brothers, as different as night and day, who are sent to attempt invade the Hellsing Organization base by Millennium.
Luke and Jan are contrast each other completely, in both looks and attitude.
Luke Valentine is always calm, even when killing. He keeps himself composed and doesn't talk more than he has to. He only shows fear after he is paralyzed by Alucard.
Jan on the other hand is incredibly vulgar, violent and more obviously a psychopath. The first line from him perfectly demonstrates this: "And so halfway through blowing me, the fuckin' hooker OD's on heroin!" Luke responds by saying he doesn't want to discuss his own ex-girlfriend with Jan.
Jan also openly displays the want to have sex with basically everything in a 6378.1 kilometer radius, while also wanting to murder everyone in that same radius.
Luke shows about 4 emotions in the Hellsing Ultimate Abridged Series: Pride, Fear, Hopefulness, and then Fear again.