Sweet Jeebus, you guys have never heard of Thanos or the story arc The Infinity Gauntlet?
Thanos was born on Titan, a moon of Saturn, to Mentor and Sui-San. Thanos is born with the Deviant gene and as resembles the Deviants—the Eternals' cousin race—more than his own people. Although treated fairly by his race, he is mindful of his appearance and becomes distant, only keeping company with his brother Eros (Starfox). During his childhood, he becomes fascinated with nihilism and death, eventually falling in love with its embodiment, Mistress Death. As an adult, Thanos uses bionics and mysticism to become the most powerful of the Titan, and is often referred to as the Mad Titan.
The Infinity Gauntlet
A resurrected Thanos collects the Infinity Gems once again and creates the Infinity Gauntlet, which makes him omnipotent. He attempts to kill half the living things in the universe, but is defeated by Adam Warlock. Warlock reveals that Thanos has always arranged for himself to be defeated because he knows he is not worthy of ultimate power. Thanos joins Warlock in the Infinity Watch and helps him to defeat his evil and good sides, as well as to cure Thor of “Warrior Madness.”
Thanos later recruits a team of Earth-bound super-villains and puts them under the field leadership of Geatar in a mission to extract a robot containing the knowledge of a universal library. Thanos uses information from the robot to battle Tyrant, a failed creation of Galactus.
Thanos is somehow trapped in an alternate dimension and employs the aid of the brother of Ka-Zar, Parnival Plunder, in an attempted escape, but fails. Thanos attempts to use the Hulk as a physical anchor back to the Earth-616 universe but is again unsuccessful. Thanos is somehow freed and quickly comes into conflict with Thor. During their battle, Thanos decimates the planet Rigel-3.
The Thanos Imperative
Main article: The Thanos Imperative
A cocoon protected by the Universal Church of Truth is revealed to be hiding Thanos, who has been chosen by Oblivion to be the new Avatar of Death. Resurrected before his mind could be fully formed, Thanos goes on a mindless rampage before being captured by the Guardians of the Galaxy
Thanos is the Guardians' only hope against the invading Cancerverse, and Star-Lord releases him to let him help. In the Cancerverse, only Thanos can slay the undying creatures that dwell there. Upon learning that he is unable to die, Thanos assists the Guardians in learning of the Cancerverse's origin. As a ruse, he surrenders to Mar-Vell in return for granting him death. When Mar-Vell attempts to sacrifice Thanos, Death is able to kill Mar-Vell first. The Cancerverse begins to collapse, and Thanos is trapped in it with Nova and Star-Lord.