Complex sentence: Hailing from the distant future, Professor Eobard Thawne was obsessed with the Flash, going so far as to replicate the accident that gave him his powers, but when he traveled back in time, he discovered that he was destined to become the Flash's archenemy.
Split into simpler sentences: Hailing from the distant future, Professor Eobard Thawne was obsessed with the Flash, going so far as to replicate the accident that gave him his powers. But when he traveled back in time, he discovered that he was destined to become the Flash's archenemy.