Devastor (Scavenger in English version) was hired by Megatron for his skills as a mercenary and a bounty hunter for Microns, due to the troubles Megatron was having with the troops under his command. Devastor claimed that at first he did not know whether to accept the contract or not, until he saw the sorry state of the Destrons after their defeat at the hands of Hot Rod and the Star Saber. His mocking lack of respect or fear for Megatron intimidated the other Destrons, as well as earning Starscream's hatred. (Source: Transformers Wiki, edited)
