The Dark Tower is a dark fantasy series written by Stephen King consisting of 7 books (and a spinoff). The work connects all of his works together. A comic series exists based off the work, and a movie/tv series is in development Hell.
Power of the Verse
The Dark Tower is an incredibly powerful verse. Each floor of the tower is infinitely greater than the previous. It has every Stephen King character ever written, including several cosmics. To top it all off, it has several higher-dimensional beings, as well as two beyond dimensional entities.
He Who Walks Between The Rows
Charlene "Charlie" McGee