How Jayel became the proprietor of the Wanton Wench is more or less a hand-waved affair by the local officials. The facts known by 'upstanding' folk are that a fresh-faced young girl by the name of Jayel came into Gatewatch, disappeared, and reappeared the aged and stern woman she is today. The facts known by the night watch are a marked decrease in drug trafficking and battered women appearing on the streets. The fact known by Jayel is that she killed a man with her bare hands, and has never looked back.
What if some crazy wizard created an artifact that empowered rodents that touched it with one random supernatural power? Preferly right out of the pages of your favorite four-color. (But only one power!) This item does not convey any sort of intelligence boost.