Complex sentence: This, as the book shows, is not the case, as Bishops are always presented as greedy, weak, temperamental, and unintelligent; usually with an adviser who does most of the in-depth thinking for them.
Split into simpler sentences: This, as the book shows, is not the case as Bishops are always presented negatively. All Bishops are presented as greedy, weak, temperamental, and unintelligent, usually with an advisor that does most of the in-depth thinking for them.