Blitzcrank come from?
According to the lore, he's an invention from Zaun.
Viktor was the head of the team who made Blitzcrank, but Professor Stanwick stole credit for Viktor's work on Blitzcrank. Professor Stanwick also stole Viktor's research to revive Urgot later on. So Viktor cut off contact with other people, and slowly replaced his body parts with mechanic parts, "a project which no one else could take credit for."