Complex sentence: At the end of the fifth season, it is revealed that the Drakh had manipulated the Interstellar Alliance into attacking the Centauri Homeworld and decided they needed Londo to be Emperor.
Split into simpler sentences: At the end of the fifth season, it was revealed that the Drakh had manipulated the Interstellar Alliance into attacking the Centauri Homeworld. The Drakh decided they needed Londo to be Emperor.