Cancerverse

Galactus, the Celestials and the resurrected Tenebrous and Aegis combat the powerful Cancerverse weapon, the Galactus Engine (constructed around the corpse of the Cancerverse's counterpart to Galactus).

Later he returned as a hero when he helped the Guardians of the Galaxy cure the Cancerverse.

The only difference was, in the Cancerverse, death does not exist.