Sith Transformers are evil Robots known to use the dark side of the force to conquer planets and galaxies. They were banned and outlawed on Cybertron and expected to never return again thus making Sith transformers want their evil Revenge against the Autobots. All Sith Transformers joined Evil Darth Grievous's Sith Legion to gang up against the Autobots to fight for control of their homeworld.