DeBeers has been a member of the Illuminati since the 20th century, and potentially even acted as its leader since then. During his rule, he ordered the assassinations of both President John F. Kennedy and his brother Robert in 1963 and 1968, respectively.
In 2027, DeBeers is still in charge of the Illuminati, and it is implied that he considers Everett to be his protégé. By this time, before being usurped by Everett, DeBeers lives in a fifteenth century home in Geneva, Switzerland. Because of his age, he requires regular treatments from Dr. Roman, who he strongly dislikes. However, they are necessary to maintain his leadership of the group because all the others, his protégé in Paris first among them, watch his possible weaknesses. During the conversation with the holographic busts of five men and two women (data tags showed their locations: Hengsha, Paris, Dubai, Washington, Singapore, Hong Kong, New York), drinking his favorite Saint Helena coffee, they report on the progress of the "their plan".
At the end of the operation in Geneva, DeBeers meets Morgan Everet at the Eiffel Tower in Paris. They recollect about the operation, and Morgan claims that, even with Bill Taggart alive, the assassination attempt has pushed the United Nations to hold a conference on regulating Mechanical Augmentation. They also speak of Bob Page, Morgan's apprentice, who has recovered Gunther Hermann from the Rhône river and his newfound respect for Majestic 12. They speak of several of their plans for the near future, including: the biochip, the cure for AIDS, the "D Project" and an experiment with manipulating the California Fault line.
After the attack on Sarif Industries Headquarters, DeBeers tries to make contact with David Sarif, but Sarif tells his Executive Assistant Athene Margoulis by e-mail to block all future calls from DeBeers "regardless of how much money he has," a conversation that can be seen on her computer when she isn't at work.
In 2028, DeBeers is in a private meeting with Elizabeth DuClare at Hotel Imperioli in Sorrento, Italy. DuClare's role as de facto head of WHO gave her access to experimental medical systems and help DeBeers fight off the ravages of time and illness, creating a special bond between them. During the meeting they talk about the other members of the Council, of Janus and his Collective, who strikes Illuminati's grand, complex plan for mankind, with DuClare that reassures him that she will unmask Janus. At this time, DeBeers suspects that Page may find the courage to oust him some time in the future, if the conditions are right.
By 2029, DeBeers is the richest person in the world.
|"By one set of criteria, Lucius DeBeers is the most powerful man on earth. He is, after all, the long-time head of the Illuminati, the organization that has controlled human civilization for centuries. By another, and probably more accurate measure, Lucius DeBeers is a human Popsicle.
About the time that the fortunes of the Illuminati began to decline sharply, and MJ12 first begun to quietly exert overt influence, 'by remarkable coincidence' Lucius DeBeers became deathly ill. His protégé in the organization, Morgan Everett, offered to keep Lucius safe in a form of cryogenic suspension. The system Everett devised kept Lucius's physical systems totally inert, while still allowing him to think and even speak. It must be a cold hell for DeBeers, but he would have never got to the position he attained if his survival instincts weren't miles beyond those of ordinary people. And he does keep busy... Everett often comes to him for advice and guidance. Will DeBeers ever be released from his icy prison to resume his rightful place on the seat of power? Of course he will. Morgan promised, didn't he?"
|- description of Lucius DeBeers, Deus Ex|
DeBeers can be found in a cryo pod in Morgan Everett's house, now a shadow of what it once was. He was put there under the false impression that when the technology was invented to help cure his ailment, Everett would restore him to his former glory. However, unbeknownst to DeBeers, the technology has already been around for some time, and Everett has no intention of ever reviving him. You can tell DeBeers the truth about Everett's deception or lie to him and tell him that Everett is still with him. If you tell him the truth, DeBeers will ask you to power down his pod, euthanizing him. Everett will scold you via infolink if you do this, but besides that, he will do nothing else. An e-mail message from DeBeers to Bob Page can be found on a computer terminal in Area 51.
- His name alludes to the powerful real life De Beers diamond cartel that in the past controlled roughly 90% of the world's diamond production. De Beers has been accused and condemned by human rights activists, economic analysts, and conspiracy theorists for a number of both confirmed and unconfirmed controversies.
- He refers to himself as "The Supreme Enlightened" and "The One,", names which are similar to those given to Siddhārtha Gautama such as the "Supreme Buddha" and "The Enlightened One."
- Despite being from southern England, he has a slight southern United States accent in Deus Ex. However, in Deus Ex: Mankind Divided, he has a fairly neutral British accent.
- An e-mail conversation between Bob Page and Morgan Everett can be found in VersaLife's Palisade Property Bank corporate vault, with mentions of DeBeers preparing to go into cryostasis due to his increasingly deteriorating health. The same email also reveals Page's intention of letting DeBeers die of natural causes rather than keeping him alive in stasis.