Technology & Combat Characteristics
Discovered by the Neo Zeon, the Gigantis is portrayed as a very destructive Mobile Weapon in terms of raw destructive power. Its armaments included an array of missiles and a double barreled energy cannon called the Glenn Cannon on its abdomen as well as limited melee and defensive shields.
The Gigantis's overall performance increases to incredible heights of speed, durability, and power; even its basic weapons increase their potency dramatically such as the "All Missiles" attack where all of the Gigantis' now Ide-powered missiles are launched simultaneously at great speeds destroying fleets of ships in one attack. Without a doubt, the Gigantis' destructive power reaches godlike status when three distinct weapons are discovered.
History
Originally called the Legendary Giant-God Ideon, this previous incarnation of Gigantis was first discovered on the planet Solo by archeologists from Earth. It was an artifact of the Sixth Civilization (the sixth sentient alien race that Earth found evidence of existing on another planet). During their attempts to analyze the various Ideon machines, a new alien race known as the Buff Clan attacked humanity. The Buff Clan feared that Earth's objective was to revive the Giant God to use against them. In order to stop them they carried out a series of attacks on the colonists, which prompted them to combine the machines to form the Ideon to fight them off.
Finding the Ideon initially to only have its fists and its bladed feet available to defend itself, the Solo colonists armed it with both missiles and Glenn Cannons. They then used it to defend against the repeated assaults of the Buff Clan. As the Buff Clan attacked their colony the colonists fled and the humans found and repaired another relic of the Sixth Civilization, a large vessel with self-contained hydroponics they named the Solo Ship.
Loading the Ideon onto this vessel the beleaguered colonists learned that Karala Ajiba and her companion were in fact members of the Buff Clan. The colonists attempted to surrender to the Buff Clan, however their efforts failed as they later learned that the Buff Clan regarded red flags as a sign of surrender and white flags as a sign of fatal defiance. Karala warned them of this, but it was too late. After these incidents the colonists attempted to escape from the planet Solo by entering Null Space (a subspace used for faster than light travel). Despite the high durability of their ship, and nigh invincibility of the Ideon, the colonists were forced to exit Null Space landing back on another part of the planet. Karala had begun to want to help the humans and explained the origin of the Giant God's power.
The Ideon drew its source from the power of Ide, an infinite energy source said to be wielded by an ancient hero of the Buff Clan. This gave it a sort of religious significance for the Buff Clan and made their efforts more fervent, especially once they discovered that it was in fact the Giant God of legend that they thought it to be.
The Ideon fought as the Solo Ship's sole defender across many strange and alien worlds as the Buff Clan pursued them mercilessly. As it did so its power spiked. The colonists began to learn that the power of Ide was activated by a need to protect something. With this power needing to constantly grow they began to learn of weapons of terrible power that were stored inside it, the Ide-powered missiles being the first manifestation.
As the colonists attempted to seek assistance from other colonies of Earth they were initially snubbed and when another colony attempted to help them, it proved too weak and the Buff Clan wiped it out. The desperate struggle to save the world resulted in the awakening of a new power and the activation of the Black Hole Cannon.
Realizing that no tactic to destroy the Ideon itself was effective (thus far only electrifying it had had any effect) they initiated a new plan to use a psycommu-like weapon to affect the minds of its pilots and paralyze them. This initially proved successful, however it led to a greater awakening of Ide that produced the devastating Ideon Swords.
Once the Solo colonists traveled to other Earth colonies the colonies shifted from skepticism to the point that they actively allied themselves with the Buff Clan. In tear-filled battles the colonists losing hope fought their way to the moon. Trying to infiltrate to a key computer facility Karala and Solo Ship captain Bess used it and calculated that the potential energy of the Ideon is indeed infinite. Following this and in a difficult situation they make the first use of the Wave-Leader Gun (a.k.a. Ideon Gun). The devastating tornado like effect is so severe that when used near Saturn it destroyed most of its rings. Foolishly they continued to use its immense power, at one point using it at low energy and tearing a swath across the Earth.
The members of the Solo Ship fled deeper and deeper into space. Their final battle occurs against the gargantuan Buff Clan ship, Bairaru Jin. This battle sees the deaths and near deaths of several key characters, an event which invokes the power of Ide and causes the Ideon to destroy much of the galaxy, including the entirety of humanity and the Buff Clan. It is alluded that this happened so that life could begin again in a more perfect form, a key theme picked up and used as backstory by Mobile Suit Vs. Giant God of Legend: Gigantis' Counterattack.
In the Ideon film "A Contact" events are repeated much the same as they were in the series, except with omissions of many connecting incidents.
In "Be Invoked" an entire new conclusion to the Ideon's saga was seen. While it ended the same way as the series, the Ideon was shown even more clearly to have a will of its own, particularly its desire to protect the infant Piper Lou and later the child of Karala and Bess, Messiah. The Ideon fights against the immense Gandow Roa, a mammoth space fortress that dwarfs even the titanic Bairaru Jin. Throughout the film the characters from Solo are given much more graphic and clear deaths until in the end Ideon is invoked resulting in a similar end to all life. The film however clearly shows the souls of those who have died communing, and explicitly sets up the future of mankind being born again as a more enlightened race, this being stated in Gigantis' Counterattack to take the form known as Newtypes.
The Zeons have uncovered what they call the "Giant God" (which is never actually called Gigantis or Ideon within the story). While investigating, Judau Ashta learns that the Zeons are planning on using Mineva Lao Zabi's Newtype powers to awaken the Giant God and get their revenge. Unfortunately, it goes out of control and begins attacking anything in sight. As Judau infiltrates the Giant God, Amuro Ray (along with Char Aznable) fights to distract it. As he nears Mineva, the spirit of Karala Ajiba and her baby appear, explaining that Gigantis remade the universe because it hoped that a new type of human – namely, Newtypes – would be the universe's salvation from war. But since this turned out not to be the case, the Giant God was set to remake the universe again. Judau also learns that he is the reincarnation of Ideon protagonist Cosmo Yuki, and violently opposes this plan. With Amuro's help, he manages to free Mineva and shut Gigantis down before Amuro destroys it from inside using Mega Zeta's High Mega Cannon, to make sure it can't do any more harm.