Rebirth to Save the World

When Su Lin traveled back to his senior year in high school, he thought he could reach the top of the world with his rebirth experience. Unexpectedly, human beings are in danger. When Su Lin killed a fish, a ball of light increased his energy. Su Lin was stunned! Is this the way to become a wild king? However, being able to dominate the world and be unparalleled seems to be pretty good!