The Debt Collector [fae, bimbofication, gender swap, transformation]

Jacob MacDonald was your average low-level thug who owed a lot of money to the wrong people. When someone shows up to collect on his underworld debts, he can't help but laugh at the well-dressed stranger, who seems more like a dapper GQ model than a mob enforcer. However, the otherworldly man who introduces himself only as "John Smith" has more than one way of making the bankrupt Jacob pay down his debts...

This short story is just over 4500 words long and involves Jacob, a brutish criminal who gets turned into a gorgeous brunette girl for his insolence, and a handsome unseelie (dark fae) debt collector who spends a few wonderful hours with her, and eventually introduces the beautiful girl to his harem.