The Demon-Slaying Tutor of Zongman

"My name is Gray Folpasta. I am a demon-slayer instructor." The protagonist travels through time and becomes Gray, possessing a mobile phone from all realms as a golden finger Travel across all realms and write the legend of the Demon-Slaying Mentor. PS: This is my first time writing a book, please give me some advice. This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.