When Lucius was born on the date of June 6th, 1966, nobody expected him to be anything other than a normal little boy. His childhood, spent in the luxurious manor on the private estate of his father, a US Senator, was as normal as every kid’s young years, excluding the extreme wealth of his parents.
The night before Lucius turns six, the Devil appears in his dreams and identifies himself as Lucifer' "real father". The Devil tasks his son with aiding the powers of evil in taking over the world. Lucius kicks off this global takeover by first murdering every member of his household, including staff, in order to obtain his father's vast fortune and make use of the political power associated with his name.
Source: Wikipedia, "Lucius (video game)", available under the CC-BY-SA License.