Temujin actually did this. There’s a book called “The travels of an alchemist” that’s a first hand account of a monk getting summoned to meet the great khan. He had to travel for months at an old age to meet him. They talked for a few days about immortality, the monk gave him some advice about trying to maybe not kill so many people all of the time. Temujin would listen politely and nod and say sure sure, and then did whatever he wanted anyway. This isn’t really doing to story justice but I hate typing on my phone.