Falling Dooooown

When a human named Jim falls down a dark hole and enters the underground, he notices that he suddenly gains a rare power, strangers tell him that they once knew him and many other strange things occur. Once he enters the gray door, nothing is the same anymore...
⚠️ Slight profanity and potty humor ⚠️
Told in 3rd person (aside from a few select POV's).
Disclaimer--
I do not own Undertale. Undertale belongs to Toby Fox, as do all of the characters except for the new characters that I created.