Who is the old man?????? Is it the father of his ex-crush???

Old man In chapter one who gambled with jaeshin n cheated to win boon. He asked to increase his life span and jaeshin swapped his with his sons. His son died and jae shin got punished to be a pup in mortal realm Old man was waiting for this moment to fulfill his revenge

He's the old man that Jaeshin plays the border game with in chapter 1. The one he loses the be to and has to grant him a wish.