Xianese cities, with the exception of three, are all located in the mountainous border regions. These serve as key outposts since they all lay on the only trails that enter the country. In total there are seven trails that can be used to enter the country, and each has a city serving as a strategic point that makes sneak attacks impossible since any invaders would have to travel through at least one of the cities into the Xianese heartland. They also serve as facilitators of trade, providing respite to the brave tradesmen that travel through the mountains that divide Xi'an from the outside world.
Is it alright if I try to assassinate you during your crowning of the prince, it would be interesting but it's your choice as Gm.
It's OK on the following conditions
1) You have a reasonable explanation about how an assassin got into such a heavily guarded place. I'd suggest just having a human servant that you brainwashed with magic but it's up to you, it just has to be believable.
@ThatOneNewGuy Wu is an NPC so you can control her too. Just stay true to character. She is informal and blunt amongst her own class but known when to be formal and respectful. She also takes her job seriously, and right now that is to babysit Mol and keep him from causing an international incident.