1. Yuelai Inn was the largest chain inn in ancient times...
2. Super deadly poison, antidotes, and concealed weapons all come from the Western Regions.
3. People who you interact with daily, if they just put on a night suit and cover their face with a veil, you wouldn't be able to recognize them.
4. The kung-fu names used by minor characters have strong literary and animalistic elements, but aren't very practical.