Tale of the Broken Hero

If you need to restart the game, you need a soul in exchange. A player from the outside got transmigrated in the game that he is playing. He became Einar Lionhart, the second battalion commander and also one of the enemy bosses of the game. Upon realizing that he became the game character, he just let himself follow the system to gain his memories back as a reward. He continues to follow it until he can’t take it anymore because those tasks are creating him to become evil.