How do we know about the human kings?

[FRedgli]

On the wiki it’s meantioned that Rashek gave lerasium to the human Kong’s who supported him during his conquests. How do we know that, it’s not cited as a wob and I dont remember any meantion if that in the books! 

 

Thanks in advance 

[Ashertliden]

https://brandonsanderson.com/annotation-mistborn-3-chapter-sixty-two-part-2/

Here ya go