Complex sentence: Michael Jai White found appeal in the story of Al Simmons, which he described as "the most tragic character I've encountered in any cinematic production", while providing the challenge of making audiences sympathize with a government assassin who comes back from hell.
Split into simpler sentences: Michael Jai White found Al Simmons'character to have a certain appeal, which he described as "the most tragic character I've encountered in any cinematic production". He says it was challenge to make audiences sympathize with a government assassin who comes back from hell.