I Killed Academy Players

One day, I entered the game "Legend of Heroes of Ahan" that I had played before, and became an inconspicuous supporting character in the Novice Village. According to the script, I was supposed to follow the protagonist of the game, Park Si-hoo, to conquer the world together, and push it all the way to the perfect ending to return to Earth. But I don't know when the story started to deviate - the female characters who were supposed to be in the team disappeared mysteriously one after another. The rest of the team were all men. The way Park Shihou looked at me became more and more uncomfortable. It was not until the eve of the decisive battle that I finally saw clearly: he was not a savior at all. He is a fellow time traveler, a murderous pervert who will do whatever it takes just to gain experience points. Those "missing" female characters, those "trophies" equipment and potions, each of them cost their lives. Fortunately, he overturned at the final level. The system took me back to three years ago, the beginning of everything. This time, I killed him before he did it. The will of the world chose me to replace him and become the new protagonist. What should I do in the future to make the game reach that... Real perfect ending?