The Cosmic Control Rod is a powerful weapon that grants its wielder the ability to manipulate cosmic energy rearranging the object's molecular structure.
Annihilus used to be its wielder until his defeat in Annihilation. As he was in a latent state, Catastrophus was taking care of both the Rod and Annihilus, but in fact the Rod was being used to prevent Annihilus to reach a mature state.
Talon and Razor murdered Catastrophus and stole the Rod so they could use it to convince Blastaar to declare war to the Positive Zone.
Annihilus regained the Control Rod and instead of wearing it around his neck he put it on the end of two handed battle axe, that he used to kill Johnny Storm, several times. But when Johnny and the Light Brigade learned where Annihilus had hidden it they made a plan to steal it. During an large battle in the Negative Zone Johnny is able to defeat Annihilus and take control of the Rod. He then uses it to control the Negative Zone battle fleet and attack the Kree fleet posed to take over Earth.