Bitter at being an outsider, Thanos becomes fascinated with nihilism, embarking on his quest to "please" death, and begins by conducting a nuclear bombardment of Titan that kills millions of his race. Thanos' mother is thought to have died during the bombardment, but years later it is discovered that he kidnaps and then dissects her.  He later travels to Earth, and prior to landing his vessel destroys a nearby car to prevent anyone from becoming aware of his existence. Unknown to Thanos, two of the family members in the vehicle survive — the father's spirit is preserved by the Titanian cosmic entity Chronos and is given a new form as Drax the Destroyer while the daughter is found by Thanos' father Mentor and is raised to become Moondragon. 
Many years later, Thanos begins his plan to conquer the galaxy; he builds a base on Earth and constructs a space vessel in the solar system that acts as a "universal translator" for his huge army of alien mercenaries, so that they can understand each other's language. It is at this time that Mistress Death - drawn by the level of Thanos' obsession and his now considerable power - manifests itself before Thanos, being an abstract entity and the personification of the universal concept of death. Thanos becomes determined to prove his "love" to Death for this sign of affection by destroying all life in the universe, and embarks on a quest to find the artifact the Cosmic Cube. It is at this time that Thanos finds himself opposed by the superheroes of Earth, who initially fight Thanos' forces in a rather disjointed fashion:
- Captain Marvel becomes aware of Thanos courtesy of his cosmic awareness and explains the threat to Daredevil, the Black Widow, and Moondragon while Thanos hunts for the Cosmic Cube.
Thanos eventually locates the Cube, and uses his minions the Super-Skrull and the Controller to try and destroy Captain Marvel, who rallies Eros, Mentor, Drax, Moondragon, and the Avengers against Thanos. Thanos uses the Cube and wills it to allow him to be part of - and therefore in control of - everything. Although Thanos is now omnipotent and easily defeats the heroes, he makes the mistake of discarding what he believes to be a now-drained Cube. Captain Marvel shatters the Cube, which undoes Thanos' wish. Thanos then discovers that Death has abandoned him as result of this defeat, and retreats. Iron Man later investigates Thanos' old base and together with the Thing battles the Blood Brothers again.
Thanos journeys into deep space and learns of the Universal Church of Truth, led by the being the Magus, a warped and future version of the hero Adam Warlock. Deciding that the Magus is a threat to his plans, and after finding the child Gamora—whose race has been exterminated by the Church—Thanos raises and trains her to assassinate the Magus. Thanos also joins forces with Adam Warlock, who is unaware of the fact that the Magus is actually the Champion of Life and that Thanos is the Champion of Death. The two eventually battle, and Thanos feigns defeat to allow Adam Warlock time to manipulate the timeline and undo the Magus. It is during this alliance Thanos secretly siphons off the energies of the Soul Gem that Warlock possesses, and after leaving Adam Warlock, Thanos embarks on his next quest to appease Death.
Thanos combines the energies from the Soul Gem with the energies of the other Infinity Gems to power a weapon that is capable of destroying a star. Thanos then plans to painstakingly snuff out every star in the universe as a gift to Death. Gamora discovers Thanos' intentions and attempts to kill him, but is mortally wounded herself. Adam Warlock's unsuspecting ally Pip the Troll is also killed.
Gamora lives long enough to warn a returning Adam Warlock, who travels to Earth and enlists the aid of the Avengers, Captain Marvel, and Moondragon. After attacking and dealing with Thanos' mercenary fleet, most of the Avengers and Moondragon storm Sanctuary I, Thanos' vessel. Thor and Iron Man follow Adam Warlock and Captain Marvel, who confront Thanos directly. Captain Marvel destroys the weapon's launcher, but Thanos then kills an attacking Warlock. Thor holds off Thanos while Iron Man destroys the weapon itself, and an enraged Thanos then defeats the remaining heroes with Sanctuary I's weapons. The cosmic entities Lord Order and Master Chaos intervene, and via a subconscious message draw Spider-Man and the Thing into the battle. Spider-Man frees the fallen heroes, and then makes contact with the Soul Gem, releasing the spirit of Adam Warlock, who then turns Thanos to stone. 
Years later, the Silver Surfer witnesses the resurrection of Thanos by Mistress Death, who feels that Death needs a champion once again. A revived Thanos decides to collect the Infinity Gems, which he takes from the In-Betweener and the Elders of the Universe. Thanos then combines the gems on his left glove to create the Infinity Gauntlet, which allows him to exceed the power he once possessed with the Cosmic Cube.
Thanos honors Death by erasing half the population of the universe, but a group of Earth's superheroes almost defeat an overconfident Thanos. He then goes on to defeat an assembly of the cosmic hierarchy (here Galactus, the Stranger, Epoch, Kronos, two Celestials, Lord Chaos, Master Order, Mistress Love, Sire Hate), and even Death finally decides to join them. The conflict culminates in single combat with, and victory over, Eternity itself. As Thanos abandons his corporeal self to assume Eternity's position, the space pirate Nebula, who claims to be his granddaughter, takes the Gauntlet. Nebula then undoes all of Thanos' changes, to shortly afterwards lose the Gauntlet to Adam Warlock. Warlock had earlier made Thanos realize that it was his own self-doubt that subconsciously engineered his defeats, and when confronted by the superheroes he activates a nuclear device in his costume, telling them he prefers death to imprisonment. With no time to deactivate the device, Thor throws his hammer Mjolnir into Thanos, hurling him miles away. Thanos, however, teleports away just as the device detonates. Only Adam Warlock - in possession of the Infinity Gauntlet - is aware of the deception, and notes that Thanos now has a chance to reform. 
Thanos does reform for a time, and is eventually given the Reality Gem by Adam Warlock to safeguard.  At one point Thanos uses the gem to resurrect the hero Captain Marvel, who died during the time that Thanos himself was dead. Thanos seeks forgiveness for his past actions and claims he wished to test the power of the gem. Captain Marvel, however, knowing of Thanos' self-doubts, guesses the truth and suspects that he has been resurrected to try and dissuade Thanos from his real goal: using the gem to make Mistress Death love him.
Thanos confesses and at Captain Marvel's request allows him to return to the afterlife. Thanos then assists Adam Warlock and Earth's superheroes against first the Magus and later the Goddess- the evil and good personas of Warlock, who expunged them to become omnipotent when possessing the Infinity Gauntlet (Although none of Earth's heroes entirely trust him after his past actions).  After fighting Thor, now strengthened by the Power Gem, in single combat, Thanos uses an invention to imprison him, and takes Thor to Asgard, home of the Norse Gods. Once in Asgard Thanos, and the Silver Surfer engage Thor's father Odin in battle, but are overpowered. It is at this point, however, that Odin discovers he is indirectly responsible for Thor's insanity, and aids Thor in curing himself. 
Thanos later discovers via an oracle a new extraterrestrial threat - Tyrant, a failed creation of Galactus. Thanos allies himself with Galactus' former Herald Terrax, the hero Jack of Hearts, a second generation Captain Marvel, and Ganymede, a warrior-priestess dedicated to destroying Tyrant. Together they attack Tyrant's base, at which point Thanos abandons the battle and taps into Tyrant's computers to learn of his origin. Thanos then steals one of Tyrant's "power orbs" - containing power drained from Galactus' Herald Morg. Thanos then confronts the entity and dares Tyrant to stop him. The battle allows Thanos' allies to escape and destroys much of Tyrant's base, at which point Thanos teleports away to safety. Tyrant is then confronted by Galactus, who negotiates the terms of a truce (including the release of other prisoners the Silver Surfer, Gladiator, and Beta Ray Bill).
Soon after this Thanos recovers his vessel Sanctuary II from the android Quasimodo, and saves the Silver Surfer and Spider-Man in the process.  Thanos is later revealed to be trapped in an alternate dimension. He employs the aid of the brother of Ka-Zar, Parnival Plunder, to attempt escape, planning to control all vegetation and cause universal havoc.  A year later a now gigantic Thanos is still trapped, and attempts to use the Hulk as a physical anchor back to the Earth-616 universe. He is, however, defeated by the Hulk and the mutant X-Man. 
Thanos reappears two years later, having escaped the alternate dimension. He now seeks the Chalice of Ruins, Map of All-Ending, and Illumination Stone, which when united will enable the user to destroy the universe. Thanos enlists the aid of the Asgardian monster Mangog and the traitor Tarakis, and storms Asgard and ravages entire worlds hunting for the artifacts. After several bloody battles, the Thunder God Thor defeats Mangog with the help of Orikal while his ally Firelord defeats Tarakis. Just as Thanos unites the items and realizes his goal, Thor dons Asgardian armor which allows him to match Thanos' new power levels and defeats the Titan. 
Thanos later requires the aid of Thor and Genis (Captain Marvel's son) against the death god Walker, who attempts to woo Mistress Death and then destroy the entity after being rejected. Thanos and the heroes are successful, and it is revealed at this time that Thanos' retaking of his vessel and previous encounters with Ka-Zar and Thor were planned and served as useful preparation for the battle against Walker.  Thanos then devises a plan to become the All-Father of a new race of Gods created by himself. Thanos, however, finds himself opposed by the Avengers, former member Mantis, and her son Quoi, apparently destined to be the Celestial Messiah. Thanos abandons this plan after having to unite with Mistress Death to destroy the Rot, an aberration in deep space that is apparently their offspring. 
Thanos once conducted extensive research on genetics, and after studying many of the universe's heroes and villains cloned them and gene-spliced his own DNA into the subjects. Although he later abandons the project, five clones survive, being versions of Professor X, Iron Man, Gladiator, Doctor Strange, and Galactus respectively. A sixth and unnamed version of Thanos also appears, and it is revealed that many of Thanos' recent encounters with Earth's superheroes were simply clones impersonating him. The true Thanos - with the aid of Adam Warlock, Gamora, Pip the Troll, Spider-Man, Captain Marvel, and Dr. Strange - destroys the remaining clones. Heart of the Universe to stop an alien pharaoh called Akhenaten who conquers Earth. The artifact makes Thanos a part of everything, and able to absorb the entire universe - even the other cosmic entities. With his newfound omnipotence, Thanos discovers that the constant resurrection of beings has caused an impurity in the old universe that only he can fix. Thanos then restarts the universe and sacrifices himself to fix the flaw.
I know, I know I cheated a bit and copied this form WIki.
Any who the 8 drop Thanos is a very good card, the probem is you have to get to turn 8 to really abuse him, or to play him for that matter.
So I submit for your approval.
The END and The BEGINNING .
4-Puppet Master(the new one)
4-Kang(one from MHG)
4- Straight To the Grave
2-Faces of Doom
4-Enemy of My Enemy
3- The return of Donna Troy
The objective of the deck is to get to 8 sub in Sam and play Thanos. Activate Sam on him and during combat attack your opponents smallest character. They will either ko that character and a few of his friends or take the damage. Then attack again as per Sam's effect, they will have to KO more characters. Then play reset till they only have 1 character. Now you can either stun that character or exhaust it and let Deathstroke kill it during the recovery phase.