Brewing a Tale (Your Insight Needed)

Hello my friends! Over the last few months ideas of stories have been swiftly dancing around my mind. But one idea captivated me the most, and that was a story about Tahm Kench. I have a many ideas to toss, and i'm looking for feedback on it. So here we go.

The General Plan The current plan is to write a long story about a young outcasted boy who accidentally stumbles upon Tahm Kench During a series of events. Tahm makes an offer to solve the boy's problems on a single condition: He returns each night to the same place to listen to a story. The boy quickly agrees to the demand, and the boy's problems are quickly solved. The boy then holds true to his agreement and continues to return every night to hear parts of the story. (Please note that this is just a quick summary of the beginning)

** Big Ideas** The main idea i had was to incorporate the story of the young, handsome gambler in Tahm Kench's lore. This could be achieved in a few ways. One thing is for sure is that for the story length i want to achieve, i would need to expand it, make it more vibrant and rich, and ultimately a wee bit more gruesome. Then, all this would be the story told to the young boy.
One Idea I like is instead of having the gambler's story be over and done with years ago, going on the same time as the boy's story is. Basically each night after the boy leaves Tahm goes to torment the gambler and toy with the gambler's life, and then the events that transfold are told to the boy the following night. But how does this contribute to the story? Tahm Kench tells the story to the boy. And we all know Tahm likes to eat things, and the more of a taste for something he gets the more fierce he becomes. So the plan is to include Unique idea I've never seen in a book. That plan is, at first Tahm Kench seems to be a polite, gentleman to the kid. No harsh words, seeming to talk almost like royalty. He doesn't want to scare the kid (maybe he even likes the boy a bit?). But overtime, Tahm becomes hungry. If he hasn't eaten recently, the story he tells the kid becomes more fierce, gruesome, and intense. The story he tells about the gambler become darker, saying things maybe a kid shouldn't hear. Talking about eating people, what he plans to do to the gambler. Then, maybe the next time the boy comes Tahm reverts back into being polite, and he says something about the handsome gambler's best friend disappearing. Or maybe someone where the boy lives has vanished. A feast for Tahm, the boy too young to understand.

Your Thoughts? I have no clue for a setting yet, as i'm just starting to read the lore about the vast amount of areas. Hate something? Love something? Ideas of your own? Confused about something? Everything is clear in my head, I don't know how clear it will be in yours. I'll do my best to clarify on stuff.

Also, this is my first post. I believe i posted this in the right spot, because i guess it falls under fanfiction making it ineligible for the Story, Art, and Sound board. If i screwed up I'm terribly sorry.

Cheers, ESD.