Complex sentence: Originally a member of Shinra's SOLDIER elite, a traumatic incident involving his true origins drove him insane, prompting him to abandon his humanity and attempt to attain godhood by absorbing the Lifestream, the source of life on the planet.
Split into simpler sentences: Originally a member of Shinra's SOLDIER elite, a traumatic incident involving his true origins drove him insane. This prompts him to abandon his humanity and attempt to attain godhood by absorbing the Lifestream, the source of life on the planet.