becomes unable to house both his own and Mar-Vell's life energy. Photon ray treatments by a Professor Savannah stabilizes the situation and brings Mar-Vell's body and consciousness to the surface. After battling the atomic-powered Megaton, Mar-Vell is trapped in the Negative Zone once again until released by Jones via the nega-bands. Mar-Vell aids the Avengers against the Grim Reaper and the Space Phantom. Mar-Vell allies himself with Mentor and Eros against the death worshipper Thanos and his forces in a war for the Cosmic Cube. Seeing the magnitude of the threat, the cosmic entity Kronos aids them by creating Drax the Destroyer, whose sole purpose is to kill Thanos. Another cosmic being, Eon, transforms Mar-Vell into the "Protector of the Universe". This provides the hero with new abilities, including "cosmic awareness". Thanos gains the Cube and uses it to make himself omnipotent. Thanos' spirit leaves his body, and Mar-Vell uses the opportunity to shatter the Cube, which was still in Thanos' hand. This undoes Thanos's actions. Mar-Vell teams with Spider-Man to battle the Basilisk and later encounters a new villain named Nitro. While defusing a bomb placed by Nitro, Mar-Vell is exposed to a powerful nerve gas called "Compound 13". Mar-Vell collapses due to the exposure, but recovers when given an antidote. The gas, however, would eventually prove to be carcinogenic and cause Mar-Vell to develop cancer. During this time, Mar-Vell has an encounter with Living Laser. Mar-Vell investigates Nitro's allies, who are revealed to be the Kree "Lunatic Legion", leading to a series of protracted battles and the eventual trial of the cosmic entity Uatu the Watcher for constant involvement in Earth's affairs. After ending the threat and aiding Uatu the Watcher, Mar-Vell briefly separates from Jones and has an encounter with a space parasite that assumes the form of former lover Una. Mar-Vell travels to the Kree homeworld of Hala, and through a protracted series of events that almost kills Rick Jones, frees himself from the manipulation of the Supreme Intelligence. During this period Mar-Vell also encounters the cosmic entity the Stranger. Returning to Earth, Mar-Vell encounters stranded Kree scientists who attempt to retrieve an inactive Kree Sentry located on the S.H.I.E.L.D. Helicarrier. This proves unsuccessful when the Sentry activates but fails to follow direction, going on a rampage. A new villain called the Cheetah attempts to manipulate the Sentry, although both are eventually defeated by Mar-Vell. The