Complex sentence: After gaining super-speed by replicating the electrochemical bath that gave Barry Allen his powers, losing years of his life in the process, and even undergoing surgery to make himself look like Barry he traveled backward in time using the Cosmic Treadmill to meet his hero.
Split into simpler sentences: After gaining super-speed by replicating the electrochemical bath that gave Barry Allen his powers, losing years of his life in the process, and even undergoing surgery to make himself look like Barry. He traveled backward in time using the Cosmic Treadmill to meet his hero.