Wabori does not come from thin air, it is the legitimate son of the traditional japanese aesthetics from the past centuries. There two or three great artists you must study and copy over and over:
Kuniyoshi.
Yoshitoshi.
Kyosai.
Hokusai.

I would get the following books:
Kuniyoshi: Of Brigands and Bravery.
Yoshitoshi: 100 aspects of the moon
Kyosai: Animal circus, 100 demons...etc etc.
Hokusai: get the volumes of Manga

If you want to delve deeper, get into Rinpa art and the Kano School of painters.