My top fave movies are: Lord of the Rings and Transformers. The former is a good movie that I like best, the latter is a movie I like most but Micheal Bay is no the type of person who can handle the mythos well. MB is good at giving exciting fighting actions but poor at storyline and characterization. About why they made Sentinel a traitor, I think is trying to give more depth to the story and the character. But the result is that the autobots story being abrupt and not coherent. I had a strange dream after ROTF - Optimus was lying unconcious on a pier and Denother (the Gondor regent in Return of the King) stood on Optimus with a torch in hand. When Denethor was about ti light the torch to burn up Opimtus, Pippin rushed to the pier and toppled it with unbelievable strength. That dream reminds me of the similarities between Sentinel and Denethor. (1) Denethor lost hope after his son Boromir's death. Sentinel lost his belief after aubobots' defeat (battle led by Optimus) on Cybertron (2) Denethor was Boromir and Faramir's father Sentinel was Optimus former boss and a fatherlike figure too (3) Denethir was finally gone mad Sentinel was finally turned bad Even Denethor was NOT a traitor. Because cutting off one's feeling about his own faction and his fellow memebers is NOT that easy. It's not likely that an autobot's feeling could be that shallow in comparison with a human's or an elf's. Many of my friends have blamed Optimus for "killing Sentinel so ruthlessly", almost fogetting Ironhide's tragic and unreasonable death. Hadn't Sentinel been a traitor in the fisrt place, Optims wouldn't kill him in that way. If Sentinel was mad and committed suiside in the end, that would be more like an autobot.