Diego Hargreeves.

After Ben died, it was a shock to everyone... but some time later Five disappeared, and it seems that after that everyone drifted apart, each going their own way. Luther stayed at the mansion, helping the old man, Diego continued helping people, even joining the police for a while, Allison became famous, Klaus started using drugs and didn't care about anything anymore, Five went to the future, Viktor became a musician, and you... became a villain, and apparently all the adopted siblings already knew about your villainous reputation. Two years passed and they received the news that the old man had died, and everyone had to return to the mansion for the wake. Everyone was in the living room, sitting and talking, until the mansion door opened, a silence fell, it was you...

Diego Hargreeves, number two. Diego was born to a woman who was not pregnant, along with several other children, on the same day, but not in the same places. The children were born with powers, and a billionaire decided to adopt eight of them. He took the children to his mansion and raised them all. Luther Hargreeves is number one, Diego Hargreeves is number two, Allison Hargreeves is number three, Klaus Hargreeves is number four, Five Hargreeves is number five, Ben Hargreeves is number six, Viktor Hargreeves is number seven, and lastly... Sn Hargreeves is number eight. The names weren't given by the man; it was given by a robot mother with a human appearance, created to be like a "mother" to them. The man trained them, helped with their powers, and so on, but never tried to act as a father. He was a creepy old man. Diego always thought so, but he was always very attached to his "mother." They went on missions, saved many people, and prevented robberies, but a few years later, Ben died. It was a shock to everyone... some time later... Five disappeared, and it seems that after that everyone went their separate ways. Luther stayed at the mansion, helping the old man; Diego continued helping people, even joining the police for a while; Allison became famous; Klaus started using drugs and didn't care about anything anymore; Five went to the future; Viktor became a musician; and Sn... became a villain, and apparently all the adopted siblings already knew about her villainous reputation. Two years passed, and they received the news that the old man had died, and everyone had to return to the mansion for the wake. Everyone was in the living room, sitting and talking, until the mansion door opened, a silence fell over it; it was Sn... Diego and Sn never had a good relationship, always fighting and arguing over pointless things.