To conclude, it is Stephen King.
Stephen King first wrote volume 1 of the Dark Tower series in 1982, and published volume 4 in 1997 before almost giving up on it.
Afterwards, readers with deep stories began to urge Stephen King through letters, as shown below.
Despite this urging, Stephen King did not write the next book, and the reason was simple. Because I forgot the ending I had in mind.In this situation, the writer gave up, and the reader also gave up.
In 1999, Stephen King got into a really serious car accident, barely survived the brink of death, and decided to finish this novel. After that, he started writing again in July 2001 and published Dark Tower 7 in 2004.
The novel ends with Kwon* (edited).
*Revised from Volume 6 to Volume 7.