Dreadwing. Starscream is an idiot and a failure who outright boasts his ambition to betray Megatron, can barely fight, can barely do anything. Dreadwing is loyal, capable, and far more crafty than Starscream. All of Starscream's battles consist of him maybe firing one missile before running away, wheras Dreadwing incorperated numerous different tactics depending on his surroundings and enemys, and from a narrative standpoint was far mor einteresting and had a bright future plot brewing. Killing Dreadwing was the stupidest thing Megatron has ever done, and is the final note in a long line of failings as a villain that firmly cement him as one of the worst Megatrons ever in my opinion.