Complex sentence: Hailing from centuries into the future Eobard became an enemy of Barry Allen/Flash and traveled back in time to 2000 to murder him when he was 11 as the elder Barry followed him back and protected his younger self, so Eobard murdered his mother Nora instead.
Split into simpler sentences: Hailing from centuries into the future, Eobard Thawne became an enemy of Barry Allen/Flash and traveled back in time to 2000 to murder him when he was 11 years old. The elder Barry followed Thawne back in time and protected his younger self, so Eobard murdered his mother Nora instead.