Shockwave (sometimes referred to as Shockblast) is a Decepticon from Transformers G1 and is one of Megatron's strongest men though he did not go to Earth with his leader instead manning the Decepticon Head Quarters on Cybertron. Logic rules this Transformers though processers and he sees emotion as a weakness preferring to base his decisions on logic rather than his own personal feelings (if he even has any).
During the four million years that Megatron and the other Transformers on Earth were unconscious Shockwave lost his left arm and replaced it with a laser canon his alt mode is some sort of laser gun that can be manned by the other Decepticons similarly to Megatron.
Shockwave died when Unicron attacked Cybertron in the Transformers Movie.
This bio comes from the tech speck of Shockwave's toy
Cold, brutal, scientific approach to war. Seeks to overthrow Megatron as leader of Decepticons because he believes logic says he would be better. As laser gun, can emit lethal beams of energy from anywhere on the electomagnetic spectrum: gamma rays, X-rays, visible light, infrared rays, radio waves, etc.. Flies in laser gun or robot Mode. High fuel use, but can be powered by nuclear sources. Often confounded by initiave, emotional thinking.