Series
There are 3 books in the Legion series.
Stephen Leeds is a genius who can master any skill in hours, but his mind copes with this vast knowledge by creating hallucinations—distinct personalities he calls aspects—to contain each expertise. He's perfectly sane; it's his aspects who are mad. A mind-bending exploration of consciousness, ident
All 3 books total 415 pages.
The Books Oracle — track the series you are partway through, and see what to read next.