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