
Īn Ultimate Nullifier was seen in Doop's possession. Although Quasar tried to use the weapon on Magus, he failed to fire it and was nullified in the process. The Reality Gem was replaced in this instance with a duplicate created by Thanos. Quasar tried to use it in an attempt to destroy the Magus, who had acquired the collective power of five cosmic cubes and a gauntlet containing 5 of the 6 Infinity Gems. The Nullifier later appeared during the Infinity War. Faced with the prospect of dying by Richards' activation of the Nullifier, Galactus withdrew.
Reed Richards threatened the use of the Ultimate Nullifier as a last ditch effort to stop Galactus from destroying Earth. It was the only known weapon in the universe capable of inspiring outright fear in Galactus. The Nullifier appeared as a small, hand-held metallic device with no apparent functionality.


Johnny Storm retrieved the Ultimate Nullifier from Taa II, the home of Galactus - as directed by Uatu the Watcher - for the Fantastic Four to employ against the threat of Galactus himself. Upon its firing, it destroyed both the Prosilican Empire and nine tenths of the entire universe, which were later known as the Barrens. The Ultimate Nullifier was created by the Watcher Emnu when the Prosilicans began to invade other planets using technology given to them by the Watchers.
