If you describe something as illusory, you mean that although it seems true or possible, it is in fact false or impossible. His freedom is illusory. false but seeming to be real or true
based on or having the nature of an illusion; "illusive hopes of of finding a better job"; "Secret activities offer presidents the alluring but often illusory promise that they can achieve foreign policy goals without the bothersome debate and open decision that are staples of democracy"