General story stuff:
- Dark Continent is sealed off from the rest of the world by the synergy of the proton missile and Getter Rays
- Ribbons (and Amuro) cooperate with Charles zi Britannia. Thusly, the Knights of Round become Special Licensors within the A-LAWS.
-Secret Society, together with the Innovades, are both sponsors of the A-LAWS
- Spheres are a system that exists that allow the user to use the knowledge of the Taiji in order to draw out the power of the Zodiac constellations, which are massive bundles of celestial energies. Each Sphere has a "partner" which share the same causality, and an "opponent" with who their powers clash.
- Origin Law is the knowledge and power of the Taiji, the primordial "power" that governs the functions of the world at large. It exists within all matter and energy, with the greatest concentrations being within the planets and stars. The Zodiac constellations are massive concentrations of the Origin Law, and the Spheres exist as a means to draw out that latent power. The Earth is a target of so many hostile factions is because it rests upon a nexus connecting the Zodiac constellations together, and is thusly the single greatest expression of the Origin Law known.
- Firebug Unit was a special black ops squadron working for the Britannia Union. They performed a lot of ugly work, and their ultimate goal was to harness Dimensional Energy and control the DMs. One of their experiments accidentally summoned Moby Dick, aka Chaine Pisteil. It went on a rampage and destroyed Odis, TX. Crowe managed to save the orphaned Esther and fend off MD, but was ultimately punished for refusing to eliminate her (the sole surviving witness). Thus, he got disgusted and left. Their commander is Marilyn Catt, the reason for Crowe's aversion to women.
- The Holy Kingdom of Insalaum is the sovereign world-state occupying a parallel Earth. It is a monarchy ruled by the Saint King, with the current (73rd) heir being Uther Insalaum. It lost some 60% of its population and half of its surface while attempting to utilize a technology called ZONE during a war with Gaiou and his legions of Dimensional Beasts. Their access to dimensional technology comes courtesy of Aym Liared, who gave Anbrorn Jius (Minister of SCIENCE, basically) the ZONE and D-Extractor, as well as the location of ZEXIS' world. Their intention in invading our world is initially thought to be securing a new home for their 500 million surviving citizens. Ultimately, Insalaum's motive is revealed to be been part of a gambit on the part of Uther.
- ZONE (Zodiac of New Energy) is a "forbidden" technology that was leaked to Anbrorn Jius by Aym during the war against Gaiou. Insalaum attempted to use it to defeat Gaiou, but succeeded only in destroying almost half of their planet's surface in the process. The ZONE protects itself by warping space to block damage, which Aym claims is stronger than 500 D-Faults (the barrier used by DMs) and would take an entire hour of concentrated fire from the whole of ZEXIS to destroy one. Insalaum deploys a total of six of them during their occupation of Earth: North America, India, Limoncia, French Polynesia, Dark Continent and the final one on the surface of Mars. The first two are sealed using the Spheres of Land Travis and Setsuko Ohara, the third is sealed by Asakim in a self-sacrificial gesture toward Crowe, the fourth is smashed by Gaiou by Carlos' request, and the fifth is destroyed by Carlos fatally utilizing Traia's ZONE Breaker device. It is initially thought that to be impossible to rescue people trapped in the ZONE until Setsuko and Land are liberated using the completed ZONE Breaker, and Asakim is saved by Gaiou.
The ZONE functions by drawing the Origin Law out of planets, which are rich in the knowledge of the Taiji. Gaiou intends to use the ZONE to power himself up in preparation for the final battle with Ba'al.
- D-Extractor is a technology that was leaked to Anbrorn Jius by Aym during the war against Gaiou. It is a device that generates Dimensional Energy in proportion to the user's own willpower. Ergo, its output is intrinsically tied to its pilot's will. Anbrorn and Ywain both appear to believe that the power sources of Setsuko's Virgola Glory, Land's Ganleon and Crowe's Brasta are D-Extractors. The personal units of each of the High Knights is equipped with a D-Extractor.
- Abyss is a rupture in the dimensional boundary line that connects the various worlds. It only opens at specific times and under specific conditions, but allows passage between worlds with the correct timing. The Eternal is able to use it to travel to the ZEXIS world on instructions from Fudou GEN who appears to be the only person capable of moving between worlds at will. The Abyss is responsible for triggering the Anti-Spiral's Human Extinction System. Because the Abyss is currently acting as a conduit between the worlds of ZEUTH and ZEXIS, the Human Extinction System calculates both world's human populations together, which exceeds ten billion and initiates the second phase.
- Swaying Scales (揺れる天秤) is the Sphere of Crowe Broust, representing Libra. Its power is drawn out in response to strong emotions such as anger or sadness. The Curse manifests as a deprivation of the five senses toward anything that is not the focus of the user's thoughts, and an inability to think of anything else. Traia develops a workaround called the CDS (Coin Drop System). Due to a lifetime of debt and financial uncertainty, Crowe has developed a post-traumatic trigger toward the sound of jingling coins. Thus, when the Sphere's Curse begins to take hold of him, the sound of a dropped coin is used to bring him back to his senses. According to Asakim, the output of the Swaying Scales and the Inexhaustible Water Bearer share the same causality, which allows them to commune together in order to draw out the knowledge of the Origin Law to cure Esther's DMification.
- False Black Sheep (偽りの黒羊) is the Sphere of Aym Liared, representing Aries. It has the power to rewrite reality into becoming a "lie". Using this ability, Aym was able to change his own death at the hands of Asakim into a "lie", allowing himself to escape unscathed. Furthermore, Aym is able to use it to make his own appearance a "lie", enabling him to take on the appearance of others. Its Curse causes the user to become unable to distinguish truth from lies. Its powers are nullified by the Inquistive Goat, allowing Uther Insalaum to kill Aym once and for all.
- Inexhaustible Water Bearer (尽きぬ水瓶) is the Sphere of Uther Insalaum, representing Aquarius. It is a royal treasure of Insalaum, and an heirloom of the royal family. Uther is the first Saint King since the first who has been able to awaken it. According to Aym, it is the most difficult Sphere to awaken because it requires a willingness to give of himself. Aym's machinations brought Insalaum to the brink of ruin in order to goad Uther in drawing out its true power. Aym's goal in instigating the current chain of events is to prod Uther into further drawing out its power so that he can kill him and steal it. After being defeated by ZEXIS, Uther is murdered by Asakim who takes the Sphere for himself.
- Inquistive Goat (知りたがる山羊) is one of the Spheres possessed by Asakim Dawewin, representing Capricorn. It is activated by "curiosity" and functions by revealing falsehood and forcing others to tell the truth. Asakim willfully "sacrificed" himself to seal the third ZONE in order to gain access to the knowledge of the Taiji in order to discern the proper usage of this Sphere. Asakim uses it to nullify the powers of Aym's False Black Sheep, allowing Uther Insalaum to deliver the finishing blow. The previous owner was female.
- Ba'al is the catch-all term for the biological and physical beings that exist as natural enemies to sapient life. Intelligent life has supposedly been at war with them since the dawn of time. The Invaders and the Anti-Spiral Tribe are considered part of this.
- Black Knowledge is a record of all events that have transpired in the past and future of the worlds. A number of characters have acquired it to some extent:
- Charles & V.V. plan to convert the human race into pure consciousness using the Sword of Akasha in order to escape the sorrowful future the BK warns of.
- Wiseman learned of the advent of a terrifying enemy that will signal the end of the universe. Attempts to undermine Relena's call to disarmament by hacking Veda and releasing classified information on the A-LAWS' atrocities in order to perpetuate the war. He wishes for mankind to evolve through constant battle in order to become strong enough to fight the Final Boss. Failing that, he brings the planet Quent to our solar system in order to entice Chirico to inherit his powers and knowledge in order to fight.
- Lord Genome acquired the Black Knowledge and chose to resist the fate it entailed. He fought alongside "the gods of light", "those who seek endless evolution", "those who sail the galaxy" and the Dimensional Generals against Ba'al. The Anti-Spiral Tribe, who learned of the potential ultimate end of the universe due to overuse of the Power of Spiral, turned against their allies and allied themselves with Ba'al. The allied forces were ultimately defeated, and the Spiral races were sealed on their respective planets. Lord Genome fell into despair and spent the next 1000 years keeping the Earth's Spiral races suppressed.
- Ji Adell Baenel and his ZEXIS world counterpart Elgan Laudic seemingly acquired the Black Knowledge. The former appears to have been driven to insanity by it and acquired a portion of the "Great Power", which allowed him to orchestrate the events of the first Z game. The latter chose to resist the ultimate fate and made preparations dating back centuries in order to protect mankind. He gave the VX to Carlos, predicting it would end up in the hands of a Sphere Reactor. He laid the groundwork for ZEXIS, an organization that would gather the most powerful swords of mankind. Even though he is currently being controlled by Ribbons Almark, he subtly made an addition to the Federation's charter that if ZEXIS is to be reformed, it can act as an independent force with the authority to police the Federation's actions.
- Gaiou is revealed to have been one of the Dimensional Generals and thus, would ostensibly have had access to the Black Knowledge. He lost his memories as a consequence of the abortive battle against Ba'al some thousands of years prior, and wandered the dimensions driven by an instinctive urge to grow stronger. He begins to regains his memories upon seeing the Getter graveyard on the Umbral Moon, and confirms his past by revisiting his past allies. As a survivor of the allied forces, he culls the weak and converts them into Dimensional Beasts in order to prepare a fighting force to face the coming evil. Though as he admits to his old friend(s) Baron Ashura, he does not believe he or anybody else can win.
- Dr. Hell's acquisition of the Knowledge allowed him to discover the location of the sunken Bardos Island begin plumbing its depths for the secrets of the Mycenae Empire. His goal is ultimately to conquer the world and unite it under his rule, in order to utilize all of mankind's means together to fight the enemy.
- Lelouch acquires some part of it after defeating Charles. Through it, he realizes what Elgan's master plan is, but does not reveal this information to the rest of ZEXIS. C.C. is implied to have it as well, as it is stated that the Code and the Black Knowledge are connected.
- Asakim most likely possesses it, by virtue of his very existence. Given his constant usage of the word "despair", it is entirely possible that his aim in gathering the Spheres is to end his own life so as to not have to bear witness to the ultimate end of the world. Or it could be that his goal involves using the Sphere to avert that future, with escaping the shackles of Naraka merely being a pretense. Or it could be that Asakim is just a stand-in for Master Therion since Green River won't stop pestering Terada about Demonbane.
- "The Gods of Light" (光の神々): My own personal theory would be Zeus and Apollonius. Zeus is one of the Mycenae Triumvirate, described as being an "all-knowing, all-powerful god", and his severed arm is the source of all Photonic Power. Meanwhile, Apollonius is the Shadow Angel of the sun, who went by the nom de guerre of the Solar Wings in life. This theory is given at least slight validation by the event in Scenario 44 whereupon Apollonius reveals that he has fought Ba'al before, and that the Getter Team were his "comrades who fought alongside of him until the ends of space and time". Could also include the Megadeuses, who are known to be part of the systems of the world.
- "The Warriors Who Seek Endless Evolution" (進化を求める戦士): The Getters and the Spiral Knights. Both Getter Rays and the Power of Spiral are described as being the powers of evolution, and Stinger claims that all who are touched by the power of evolution yearn to become an "infinite" existence.
- "Those Who Sail The Galaxy": Most likely the Vajra.
- The Dimensional Generals (次元の将): Four individuals capable of freely traversing the parallel worlds. They fought alongside the other heroes to defeat the forces of Ba'al countless eons ago. They are supposedly all dead with the exception of Gaiou, who lost his memories and wandered the worlds driven by an instinctive urge to grow stronger.
- Aym Liared: Defeated in battle by ZEXIS in the ruins of Tokyo. His False Black Sheep Sphere's powers are nullified by Asakim, who uses the Inquistive Goat Sphere to force the truth out of him. His real name is revealed to be Hamal Algo, who was originally a researcher who founded his entire career upon lies. After being forced to see his lies for what they are, he suffers a mental breakdown and is killed by Uther Insalaum, who takes his Sphere.
- Uther Insalaum: Defeated in battle by ZEXIS on the Martian surface, while attempting to use a final ZONE device in order to stage a final assault on the Earth. Ultimately, the truth behind his actions is revealed during the final battle. He knew that any attempt to forcibly subjugate Earth's population would result in bloodshed between his people and the people of Earth in the future. Therefore, his goal was to portray himself as an incompetent (and if necessary, bloodthirsty) ruler in order to alienate himself from both his own people and the people of Earth. He allowed Aym to act, using Aym's own Sphere as a means of masking his true intentions. His ultimate hope is that Crowe will become strong enough in the process of fighting him to defeat him and take his Sphere, and together with Marguerite become the saviors of his people. He is subsequently killed by Asakim, who takes his Sphere along with Aym's.
- Asakim Dawewin: Sacrifices himself to seal the third ZONE device, seemingly as a gesture of good will toward Crowe. However, it is revealed that he did so in order to immerse himself in the knowledge of the Origin Law and, in doing so, discern a means to defeat Aym and his False Black Sheep Sphere. He is subsequently freed from the dimensional interval by his comrade Gaiou, and his curiosity in plumbing the secrets of the Origin Law activates the Inquisitive Goat Sphere, allowing him to nullify all of Aym's powers. At the final battle on Mars, he is sealed by the three Sphere Reactors (Land, Setsuko and Crowe) in the ZONE but quips that he'll be back soon enough. As of the end of the game, he has four Spheres: Aries, Aquarius, Capricorn, and one unnamed Sphere.
- Carlos Axion Jr. - Former richest man in the world, who donated all of his money to the reconstruction effort as penance for his culpability in the Broken World Incident. Becomes a salaryman in the employ of Scoat Lab, acting as Esther's manager in her duties as a rookie DM Buster. Becomes rich again after playing the stock market in his spare time. He and Gaiou consider one another to be important friends, and the latter smashes the fourth ZONE device at Carlos' request. When the forces of Ba'al begin to stir, they part ways after promising to eat hotdogs together some day. Sacrifices himself utilizing Traia's prototype ZONE Breaker on the Limoncia ZONE device, as the device requires the life force of the user as catalyst. Upon being forced to reveal his motives by the Geass placed on him by Lelouch in Hakai-hen, he reveals his intention to leave Crowe with a debt he can never repay in order to reach Libra's highest element level.
