Cy-Kill was one of Megatron's gladiator colleagues back in the days, and got his arm cut off during a match against him. The Route of All Evil He got better in time to be part of the crowd that cheered on Megatron when he killed EmirateXeon. The War Within #2
Cy-Kill is a repeated easter egg appearance by the GoBots character of the same name. But, like, GoBots were totally lame, so wouldn't it be hilarious if he was repeatedly killed over and over again because he was lame? Yeah!
The GoBots version of Cy-Kill (like all GoBots) was actually a cyborg and not a robot, while his Transformers counterparts are probably 100% robotic.