Heartforge by Patrick G Laplante

To heal his heart, he must forge it anew.
Recent events have proven too much for Cha Ming. His heart is broken, and his soul is shattered. He cannot move. He cannot speak. His friends worry for his safety.
Soul trauma is difficult to heal at the best of times, and to do so, the Monkey King calls in an expert. He sends Cha Ming to the Heartforge Realm, the place where legends are born and heroes are made.
Cha Ming isn't happy with this arrangement, but he's too busy surviving to complain. The Heartforge Trials aren't for the faint of heart, and less than one in four ever make it.
Yet there are far worse fates than death. There are many who pass the trials but lose themselves. The realm doesn't just train heroes, after all, but villains as well. The difference is often a matter of perspective.