In his quest for the Enigma Force, Argon sent the Death Squad to retrieve the three keys of the Enigma Force they held. The Micronauts refused to submit and engaged Argon's minions in combat. However, the Whirldemons attacked, killing everyone in their path, forcing Rann to leave and unlock the Tomb of Wayfinder to access the Enigma Force to stop them. Ampzilla and Devil fought each other while Acroyear fought Battleaxe. Ampzilla's gunfire kept Devil at bay, who was shielding himself with a slab of rock, until Acroyear threw his foe on Ampzilla. Devil then threw the slab on top of the two.
The Micronauts fled to Earth, landing in a school, pursued by the Death Squad. Ampzilla selected Devil as his prey, this time accompanied by Lobros, who was telepathically controlling a Lobstros. While Devil was having trouble with Lobros, Ampzilla turned his attention to slaying Bug. Devil helped Bug by throwing a globe at Ampzilla, which knocked him out.
Having just freed Prince Pharoid from being tortured by Argon's Dog Soldiers, Acroyear and Bug were suddenly confronted by the Death Squad, springing the trap that had been set for the two Micronauts.
Ampzilla and Battleaxe both attacked Acroyear, but the Micronaut eventually yielded with the arrival of armed Dog Soldiers and with Bug close to being killed.
The Death Squad accompanied Acroyear and Bug, who were now their prisoners. However, Acroyear broke free and tackled Ampzilla first, causing his head guns to shoot at Battleaxe before throwing him at Centauria. Again with Bug threatened, Acroyear surrendered.
The Death Squad, including Ampzilla, was on sentry duty to ensure that Acroyear, Bug and Pharoid did not escape the Arena. However, Huntarr and Marionette, initially hidden in the viewing stands, attacked the Death Squad from behind, with Ampzilla down after being rammed by Huntarr. Fighting broke out across the Arena with civilians fighting Dog Soldiers until the dark form of Karza ripped out of Argon's body; grabbing everyone's attention momentarily.
Marionette rallied the Micronauts in the Arena to fight past the Death Squad to meet the newly resurrected threat of Karza. Ampzilla fired at Huntarr before attacking Acroyear, demonstrating his loyalty to the Baron. However, Acroyear, having recovered his weapon, skewered Ampzilla's chest with his energy sword, killing him.