When the original Decepticon army departed Cybertron to attack the Ark, Megatron put Shockwave in the position of Guardian of Cybertron while he dealt with the Autobots. However, when the Ark crashed after the Decepticons boarded it, Megatron was left deactivated on Earth for four million years, and Shockwave remained in control of the planet. Four million years later, when Megatron was reactivated, Shockwave made contact with him (although how he knew he was alive is unknown) and assisted in building the spacebridge to traverse the distance between Earth and Cybertron.

Having not crashed to Earth with the other Transformers, Shockwave was not given an Earthen form, and retains his original Cybertronian mode of a giant ray gun, commonly termed a 'space-gun'. In this mode, Shockwave can fire massive blasts of energy with pinpoint accuracy. He can also be manually operated (why is unknown), as demonstrated by Bruticus (Ref: "The Revenge of Bruticus"). In robot mode, Shockwave has an ion cannon in place of his left hand.

Shockwave served Megatron loyally, if from afar, throughout the Great War, until Unicron attacked Cybertron in the Earth year 2005, when it was totally under Decepticon control. Shockwave was seen attempting to mobilise the Decepticons in the midst of battle, but he was not seen again following its conclusion, and was presumed destroyed in the conflict.