Immortality Martial Arts: When I Kill the Enemy, I Become Stronger

As soon as you time travel, you become the most wanted criminal with the highest reward. You find that you have a proficiency system, and as long as you practice, you can increase the progress of your skills and magical powers. Moreover, you also discovered that as long as you kill the enemy, you can become infinitely stronger! By killing one person, you can push past your physical limits. Kill hundreds of people, and you can physically resist a nuclear bomb. By killing a thousand people, you have surpassed the upper limit of warriors in the world. After killing thousands of people, you gained immortality. You are the only true immortal in the world. Kill millions of people, cover the sky with a snap of your fingers, and invade the universe and galaxies at your fingertips. ... Finally, you discover that all the heavens and worlds respect you! This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.