St. Cloud are one of the Cabal families, and are known for being the cruelest. They fund The Edison Group, but their reasons for doing so is unknown. Where they are based out of is unknown. Their current CEO is Lionel St. Cloud, and we do not know who is his heir. Troy Morgan, when speaking of a fellow bodyguard who once worked for the St. Cloud's, claims that they run their cabal "military style." He didn't give further details.
The St. Clouds are mentioned throughout many of the Darkest Powers and Darkness Rising books. It is known that the St. Clouds want the Genesis Project back under control and that their competition regarding the Phoenix Project are the Nasts.