"The Father" was an unidentified elder in Vishnu. He hired the Marcus Clan and Hunter D to rescue his daughter from Baron Mayerling. [Wikia]

He is ready to pay $10 mln. (considered to be a very big sum) in order to save his daughter. However, allows D to kill Charlotte is she has already been 'baptized' by the Noble. When D demands twice as much for that ($20 mln. is an enormous sum) agrees to pay the money.