The Cosmic Cubes are powerful objects which store reality-altering energy. The Cosmic Cubes are able to rewrite reality and do virtually anything their master wishes. A Cube's master is able to create planets, augment or negate other people's powers and skills, and so on. The Cosmic Cubes are created by the " Beyonders" from the unknown dimension of Beyond. The Beyonders made the Cosmic Cubes in order to test people's desire and evolution processes. The Beyonders also desired change in the omniverse.
The Cosmic Cube could only be obtained by projecting a particular type of energy which would open a rift to the source of the Cosmic Cube's power. The cosmic energy flows through the rift and is then stored in a matrix.
The Skrull scientists obtained a Cosmic Cube. The Cosmic Cube then developed sentient life and called itself the Shaper Of Worlds. The Skrull emperor wanted to rule as God king and used the Shaper of Worlds to do so. The Shaper of Worlds betrayed the Skrull emperor and destroyed a large part of the kingdom.
He then went on to tutor other sentient Cubes.
Cosmic Cubes on Earth
The Cosmic Cube was first discovered by A.I.M. in an experiment with an energy called "X element". The A.I.M. wanted to study of the strange energy which mutated George Tarleton into the powerful MODOK. The energy was so powerful that it was able to drive MODOK mad. The Red Skull wanted to steal the Cosmic Cube and succeeded in doing so. Despite the Cube's omnipotent powers, the Red Skull easily overpowered Captain America but later loses the Cube as the Red Skull was too confident. However, the Cosmic Cube altered reality which caused an entire island to sink and was then believed to be lost forever.
A fisherman discovered the lost Cube and transformed his village into a rich place. The Red Skull finds out about the lost Cube and sends his allies to obtain it for him. The Red Skull takes back the Cube and tries to confront Captain America again. However, the Skull loses the Cube to A.I.M. and MODOK and the Cube is apparently dissolved.
Retrieving the Cube
MODOK eventually retrieved the Cube but lost it to Thanos the mad Titan who used the energy of the Cosmic Cube to win Death's heart. Thanos, realizing the Cube's tremendous power, uses it to confront the Avengers and Captain Marvel. Before losing the Cube, Thanos absorbed the Cube's energy and becomes virtually omnipotent. Thanos then realized that he now has no need of the Cube and abandoned the Cube's energy. The Cube's energy is reabsorbed into the Cube once again and Captain Marvel uses the Cube to return everything back to normal but instead burns out all of the energy stored in the Cube.
The Cube is then confiscated by Project: Pegasus or research. The Cube then began to regain it's reality altering powers and played a huge role in the development of Aquarian. A renegade A.I.M. scientist named Victorius took the Cube and tried to use it to create worldwide entropy, but he was stopped by Captain America, the Thing, and the Man-Thing. It then went into a dormant phase, seemingly having lost all its energy.
However, the Cube was really developing sentience. A.I.M. stole it and their lead scientist, Bernard Worrell, used it to change the world into a Technopolis. However, he wasn't in full control of the Cube and he started to go mad. The Cube started getting its own ideas about what to do, and eventually developed sentient life and named itself Kubik .
Molecule Man and the Beyonder
The Beyonders have created a force which powers Cosmic Cubes. It comes through a rift in reality when those who wish to collect the force are ready. When Owen Reece had his ludicrous accident, he inadvertently tore a hole in reality where no force field was waiting on this side to trap the unleashed power. The field should have been there, whatever the force which came through the rift did to shape the field, it did. But Owen was not a field. Still, he absorbed part of the energy which came through the rift. He did not become six-sided, though he did become a component of great power, although still not quite up there with Eternity or the Living Tribunal.
The Beyonder is the greater part of the sentient force which came through the rift, lacking a containment vessel. A cosmic cube has no desires because a Cosmic Cube is complete in itself. It shapes the world with others' dreams. It satisfies others' desires. Molecule Man accidentally opened a rift through the atomic machine and traveled to the source of the Cosmic Cubes power. However, the cosmic forces which went through the rift hadn't been stored in a matrix which allowed the birth of the Beyonder.
The Shaper of Worlds and Kubik explained the origin of the Cubes to the Beyonder and the Molecule Man, and then helped them become a new Cube, which eventually evolved into Kosmos. Reece split off to become his own person again.
Infinity War and Infinity Crusade
The beginning of the Infinity War began with the collection of five cosmic cubes by the Magus. With the help of their power, he was able to obtain the Infinity Gauntlet. After his defeat the cubes were secretly stolen by the Goddess. She continued to gather more and more cubes from different dimensions.
In the end, she had collected 30 cosmic cubes. She combined them into one single force called the Cosmic Egg. She used it to brainwash the entire universe.At the time, this was the most powerful creation in existence. This is the beginning of the Infinity Crusade.
It was revealed by Mephisto that the Cubes were once sentient beings and their morals apply to the wishes that can be granted, and not all things are possible with the cubes. This can be overridden though, if enough people wish the same thing in unison it can go against the cubes own wishes. He exchanged this information in exchange for a cube of his own when the Goddess was defeated. Thanos did follow through on this bargain, but tricked Mephisto by giving him a powerless cube, saying Mephisto never specified that he wanted one with any power.
The Red Skull
The Red Skull was still obsessed of the Cube's powers and created imbalance Cosmic Cubes. The imbalance Cubes were taken by Korvac and later the Grandmaster. The other Cube was seemingly rendered useless.
Guardians of the Galaxy
In order to stop all possible futures from becoming futures ruled by the Magus, Kang the Conqueror gives the last remaining Cosmic Cube to Starlord in order to defeat him. He then sends him and the other Guardians of the Galaxy to the moment before Adam Warlock becomes the Magus, and Starlord uses the Cube to change Adam back into himself. But this is only temporary, and Starlord is forced to kill his friend and teammate.
In the Ultimate Universe the Cosmic Cube fell from the sky above the home planet of Thanos, crash landing at his feet. With the power of the Cube, Thanos would attempt to control all of creation. Thanos was narrowly defeated, and at an incredible cost of lives. Later in history the Fantastic Four would encounter Thanos in his home dimension after meeting the Seed Nineteen. The Four escaped Thanos, but unknown to the team Thanos had seized this opportunity by planting the idea for the Cube's design in the one person capable of creating one: Reed Richards. Reed realized the spectacular power that the Cube could generate, and was fixated on creating one. In his first attempt to harness the kind of power needed to create the Cube Reed locked onto what he thought was a distant star, and summoned the Silver Surfer to Earth. Seeing the unhappiness and suffering of the Earth's residents the Surfer summoned his master the Psycho Man.
When Reed finally succeeded in creating a Cosmic Cube he caught Thanos's attention. Reed attempted to use the power of the cube to protect New York City and the entire city was lifted out of the Earth to Thanos's dimension. Thanos's power was far greater than Reed's, and even though Reed had the Cosmic Cube he was inexperienced in its use and unable to defeat Thanos. Reed was seemingly killed by Thanos, but actually changed himself into an energy being to escape obliteration. Ben Grimm, with the help of Thanos's daughter, was able to bring Reed back out of the shell he had created for himself. They traveled back to Earth where Thanos had already enslaved many of Earth's most powerful heroes. They were able to distract Thanos long enough for Reed to give himself back his body. In order to defeat Thanos, Reed would unlock a small portion of the Cube's power which he had previously blocked off. With this safeguard gone, Thanos's body quickly died and disintegrated.
Thanos's own infatuation with Death would be his undoing. His desire to be dead overcame him and killed him. In trying to decide what he would do with the all-powerful Cosmic Cube he would fulfill the ancient legend of how Thanos originally came to find the Cube.
Reed opened a very small rift in space and time. He dropped the Cube through the rift above Thanos's planet, which plummeted to the ground and landed by a younger Thanos. In this paradoxical move, the Cosmic Cube which Reed developed would be the original Cube that Thanos had discovered and nearly destroyed the universe with so long ago.
The Blueprints for the construction of the Cosmic Cube were stolen from the Baxter Building by A.I.M with the help from the Red Skull who was apparently some how came out of retirement, during the theft the Red Skull brutally beats up Captain America and throws him out of the Helicopter taking the Blueprints.
It is later revealed to the Team that the blueprints that had been stolen where of the Cosmic Cube and that the A.I.M are Two days away from the completion of the Cosmic Cube but when the Avengers the black ops of the S.H.I.E.L.D. go to A.I.M's base of Operations in Alaska it is revealed that the Cosmic Cube is finished and the Red Skull has used it to kill every member of A.I.M by making them eat each other.
The Red Skull uses the power of the Cube as an advantage over the Avengers but he isn't in full control of the Cube as he states while battling the Avengers that he needs practice. Although the Skull is beating each member of the team, War machine rips out the hidden nuke inside his armour and damages the entire armour, Hawkeye turns the nuke in to his children's toys and their bones, Black Widow makes her go through the interrogation in Bosnia, makes the Nerd Hulk believe he destroyed the Cosmic Cube but then blasts him away into a Mountain and threatens the Red Wasp that he'll make her go through her Husbands death again but before he is able to do that he is impaled by Captain America on one of the two rods that protrude from the nose of the stolen Teleporter Jet.
The Red Skull is taken to a hospital and kept alive long enough for his mother, Gail Richards, to say her goodbyes. The Red Skull explains to Nick Fury his only use for the Cosmic Cube was that he wanted to turn back time and prevent his father, Steve Rogers, from being lost at the end of the war so that he could grow up with him and lead a normal life, rather than the one he was given by fate.
After the credits role in Thor, Jane Foster's mentor Erik Selvig is taken to an disclosed location to meet up with the Director of SHIELD, Nick Fury. Fury assigns Selvig to study the recently acquired Tesseract, since he believes it to be the source of vast amounts of energy and power. At first Selvig seems to be against it, eventually Selvig agrees, and it is revealed that he is possessed by Loki , who exclaims "Well I guess that's worth a look".
Captain America: The First Avenger (2011)
In Captain America: The First Avenger, the Red Skull knows about the Tesseract on Earth that was originally Odin's crown jewel in his treasure vault. He finds a replicate buried in a tomb, which he destroys, leading him to find the original Cube which glows with a strange, blue light, and has his scientist Arnim Zola design a machine to extracts the Cube's raw power. The machine works, and it appears the cube has an endless supply of power that can be extracted and stored in containers that generally act as munition for handguns, tanks, and other weaponry used by Hydra forces. Cube-powered weapons fire appears as glowing blue energy projectiles that completely disintegrate humans in a split second. Only Captain America's vibranium shield is able to deflect these projectiles. Eventually Captain America disturbs the machine that holds the Cube, and it seems to "short circuit". Images of space appear. The Red Skull picks up the cube and seems to be slowly disintegrated, or perhaps transported. The cube is then lost at the middle of the ocean, but later found by Howard Stark, who was in search of the Cube and Captain America.
The Avengers (2012)
The Tesseract in the Avengers acts as a gateway through the worlds and realms, Loki uses the Tesseract as a means of transporting the Chitauri from their realm to Earth. But before the invasion and Loki's entrance through the portal that Tesseract opened, he made a deal with an alien being known as The Other, he bargained that he will give Loki a sceptre, and his masters army to invade Earth, Loki will have give his service as well as the capturing of the Tesseract. . Which Loki fails to do.
S.H.I.E.L.D was planning to use the energy of the Tesseract for Phase 2, creating Weapons of Mass Destruction, just like Hydra in WWII, in order to combat any alien threats that they might face in the Future. The cube is also a reflection and a message to the universe that the Earth is being prepared and is ready for a higher form of War, as Thor claims. Eventually Thor takes the Tesseract back to where it belongs , Odin's Treasure Vault in Asgard.
The term Tesseract comes from the term to describe a 4-D equivalent of a cube.