Do I Need to Kill the Villain at the Beginning of the Dungeon?

After Jiang Weiran accidentally traveled through time, he was forced to kill the villain Ghost King. At the beginning of the dungeon, his heart was thrown out and made into the Ghost King's most sincere subordinate. What will happen if a heartless living dead accompanies everyone to clear the dungeon? Important note: There is no CP, nor are all the supporting characters. Readers are free to eat whatever they want.