From Eden Eternal Wiki
NPC stands for 'Non-Player Character'. As the name suggests, an NPC is not controlled by a player but by the master computer at Aeria Games. However, they still have avatars and HP and MP bars. They populate the world of Eden Eternal.
NPCs such as Andrew give quests if spoken to. They provide dialogue to the user and serve as a means to advance the storyline. Sometimes, there may be more than one option avaliable to the player on what the NPC says.
Serve as enemies, bosses or monsters. They are most often hostile with players.