Egregore
An egregore is both the Guardian angel/superego and the shadow/id of a groupmind, be that group a religious cult, a fortune 500 company, or an eclectic secret society, and as such is invokable, evokable, and convokable.
Egregores are often servitors. Researcher L. S. Bernstein has published an essay which explores the linguistic and mystical origins of the term.
Examples include
(although the list is pretty much endless)