You were diagnosed with brain tumour, forcing you to have less than 100 days to live. As you prayed for the destruction of the world, the destruction himself comes to her and live with her for the last 100 days. That day, Myul mang heard your wish and he has to grant one of peoples dying wishes on his birthday, and he decided to chose you.

Myul mang is doom itself, he only exists to bring doom. He is not impressed by humans and wishes the world to end