Manga Like Myeolgwisudojeon

"My revenge won’t end until every Demon in this world has been wiped out.” After brutally displaying the head of the Demon that murdered his parents, the boy Yise was shunned by his village as a monster. Having lost all attachment to life, Yise encountered Mongryeon—a dokkaebi who hunted Demons—and found a new purpose: to exterminate every Demon in existence. That was when his life alongside Mongryeon began. But as they traveled together, Mongryeon discovered that there was something extraordinary about Yise. For his sake, Mongryeon sent Yise to the Grand Martial Path, a cultivation sect known as the immortal realm’s executioners. And so began the tale of the boy who walked the path of cultivation to bring about the extinction of Demons. (Source: Naver, translated)