Yuukoku no Moriarty

From Viz:
In the late 19th century, Great Britain rules over a quarter of the world. Nobles sit in their fancy homes in comfort and luxury, while the working-class slave away at their jobs. When young Albert James Moriarty’s upper-class family adopts two lower-class orphans, the cruelty the boys experience at his family’s hands cements Albert’s hatred of the nobility he was born into. He asks the older of the two boys - who has a genius mind and a killer instinct—to help him rid the world of evil, starting with Albert’s own family.