Not much is known about Sergio's past. He is part of the Kings, and is in charge of styling their hair to resemble the pre-War King. He only agrees to style the hair of official Kings members, and takes a lot of pride in this ability.
xbox360ps3 Sometimes Sergio isn't there. He cannot be found anywhere in the building, and exiting and re-entering doesn't seem to help, nor does waiting. He appears only after the Courier has killed a significant number of Kings and the King himself. [verified]