The Zero Index Incident

The Zero Index Incident is the name of the destructive apocalyptic event that occurred inside of Academy City and leveled over 90% of it, resulting in around 1.8 million deaths and the widespread destruction of local infrastructure and schools. This event would ultimately lead Touma Kamijou on a quest to bring Monolith to justice.

Events Prior to the Incident
The evening of the incident, much of Academy City was in the midst of school festivals around many of the campuses. Given that Academy City has such a dense population, it was unsurprising that gridlock had essentially reduced any possibility for individuals to leave the city during the chaos. Still, during the events little of note happened.

Members of Judgment and Anti-Skill were not reporting any unusual activity prior to the Incident, and it was only five minutes until the Incident that reports began flooding about psychic espers becoming feverish and ill due to a sudden burst of strong emotion. During this, Anti-Skill mobilized in an effort to contain the situation.

During this, Touma Kamijou had actually skipped the festival and was resting at home awaiting the return of Index, a roommate and close friend who lived with him. Her exact whereabouts during this time are unknown as she was killed before she could be interrogated.

At this time, unbeknown to the people in Academy City, Monolith was engaged in combat with Omega Zero and was losing momentum quickly. Monolith had lost large amounts of energy and was on the back-swing, quickly becoming unable to handle Omega Zero's onslaught. Literal seconds before the incident, Monolith had been struck by Omega Zero and a ripple in reality had opened, resulting in Monolith and Omega Zero to appear in the sky of Academy City as large meteors.

Incident
During the zenith of the fireworks ceremony, the public quickly became alarmed when the sky had become exceedingly bright, and only moments after, both Omega Zero and Monolith struck the ground. After a brief moment, Omega Zero then rose upwards, and released what Subjugation calls a "Barrier Crash". Within seconds, Omega Zero's energy had fired over much of the city and was directed at Monolith. The resulting burst completely vaporized everything in its path for the first mile and then proceeded to release a wave of energy that was not unlike a wave of heat and melted every object in its way and burned or melted nearly any person in its path. Autopsies concluded the deaths likely occurred in seconds as the bodies were cooked both externally and internally. It is estimated that this blast killed over 1 million after it was immediately activated.

Monolith began doing everything to avoid Omega Zero's attacks and survive long enough to recharge some energy, however the blast from Omega Zero leveled about 60% of the city instantly, and destroyed much of the electrical infrastructure, basically making it impossible to garner any acceptable electrical output from nearby sources. Due to the possibility of destroying the planet outright and also take several nearby Subjugation outposts along with it, Monolith effectively decided to wait out the fight as long as possible.

Monolith's petawatt generator has a potential capacity of 1 quadrillion, often kept just below to avoid a blowout, and is regularly used to heal and fire off attacks while refilling energy and stamina through the body. Due to the length of the battle, constant regeneration of burned tissue, stab wounds, and energy-based blasts fired at Omega Zero, it had dwindled down quickly to 400 million, a small fraction of its maximum capacity, and without refilling, the battle would end either requiring Monolith to attempt something drastic, or with Omega Zero outright killing Monolith. In comparison, Omega Zero had proven to be far too lethal, his constant energy regeneration meant he was around 100%, fighting as if the battle hadn't even taken more than a few seconds despite it going on for almost an hour.

To Monolith's complete surprise and luck, the answer would come in the form of Touma Kamijou

Touma Arrives
During the initial blast, part of his building had been sheared right off, leaving a sea of fire and charred bodies along with toppling buildings and twisted metal. Realizing the severity of the situation, he quickly fled his dorm to safety and hoped to escape the situation before remembering Index had not yet returned home. He managed to contact one of the students at another school, a young Misaka Mikoto, who was looking for a friend of hers, but in the chaos couldn't be found. She had been looking for around ten minutes, but the sea of corpses had brought her down to her knees and she wasn't mentally capable of proceeding.

Touma figured that if her friend was a member of Judgment, then it was likely that she had made her way towards victims to get them free, as Judgment would likely be pulled back to allow Anti-Skill to deal with the situation. As they discussed this over a brief several minute conversation, multiple Subjugation Warships had arrived in space via warp and began attempting to precision strike Omega Zero. Touma wasn't entirely sure what was going on, and made his way towards the battle in expectation that Index may be behind the situation with such powers as her John's Pen.

During this, Touma could see laser blast after laser blast detonating near the battle, however despite the sheer size of the ships, they weren't firing what were clearly bigger arsenals. Monolith was amongst the fight, and couldn't risk warping to a Warship and bringing Omega Zero along, possibly killing millions of soldiers and demolishing an entire space-vessel which would likely crash to the surface of the planet and kill millions more. As such, the weapons specialists had been told to utilized focused laser beams used for glassing small targets. The blasts had done considerable damage to the ground, however Omega Zero proved to be significantly more durable, and showed very little sign of damage.

This battle of attrition seemed to be over with Monolith now barely holding onto 20 million watts of electricity, and the supply dwindling very quickly. It would possibly be over in just fifteen minutes, maybe even less, depending on how many more barriers Monolith would have to use to avoid lethal damage. During this, Monolith had been rapidly changing forms to various individuals in the hopes of dealing ranged damage to Omega Zero in any amount, but sadly it wasn't working. Additionally, transforming into Omega Zero proved to be too difficult, his anger and emotional fluctuation was unstable, and Monolith found reading his mind to be far too difficult due to the simple-minded and narrow thinking Omega Zero had. Normally, reading the mind of the target was easy, however this had been the first time Monolith actively tried reading Omega Zero's mind, and the sheer blind fury made making any semblance of his mind a dead prospect.

It was around this time that Touma managed to reach the area of the fight alongside Misaka, who had come along with him in hopes of gaining some answers. Omega Zero tried to strike Misaka first, struck by an errant burst of lightning Misaka had created to defend herself. In a quick realization, Monolith managed to grab the young woman and began actively leaping around to avoid Omega Zero while telling the girl to let loose as much electricity as possible. As such, Monolith managed to climb back up in watts very quickly, and amassed around 1 billion in a matter of minutes. Unfortunately, sustained electrical bursts were tiring, and Misaka was having a hard time doing anything further.

During this, Touma had managed to come in contact with Omega Zero. Unbeknownst to Monolith, Touma had a special ability: Imagine Breaker. When his right hand contacted Omega Zero, he had temporarily shut down before rebooting in nanoseconds upon Touma's hand disconnecting. Omega Zero wasted no time, and quickly lopped off Touma's hand at the wrist before following it up with an attempted kill. Monolith had let go of Misaka and launched at Touma, managing to grapple the young man and his severed hand, and healing it back on via magic. Touma didn't entirely understand what had just happened, but was certainly grateful not to bleed to death. Unfortunately, Monolith quickly realized that Omega Zero already realized the danger inherent in Touma living, and was making many attempts to strike him dead, which Monolith attempted to save Touma from by moving him around the battlefield. Unfortunately, playing escort mission proved to be very hazardous, and Monolith took dozens of strikes in the fight. Monolith wasn't sure there was any chance of getting close enough to Omega Zero for a second touch, he was too alert to what had just happened and was clearly watching their movements. Their solution came in an entirely unintended distraction: Index.

Index dies, Omega is defeated
Moments before Omega Zero's death, Index had wandered into the area. Sadly, because of her death, nobody is sure what she was doing there. Touma later assumed that she survived the initial blast as he did, and began running towards the battlefield in the expectation of finding Touma and helping. wherever she had been, she arrived almost ten minutes after Touma, and ran around a pile of wreckage only to catch the focused Omega Zero off guard. Index was quickly sliced in half and part of her body was completely decimated by another massive Barrier Crash, this time fired into a section of the city that hadn't been hit. Ultimately, the death count, including Index, was around 1.8 million after investigation.

The brief lapse in focus allowed Monolith to throw Touma at Omega Zero. Before he could properly react, he attempted to change his focus and swiped his blade at Touma, missing because Monolith had predicted this would happen once he was startled. Monolith had leapt behind Touma and was actively moving faster than he was, grabbing his arm and pulling him to the side, avoiding the vertical slice. From here, Touma's arm connected with Omega Zero, who quickly deactivated. Monolith held Touma's hand down, and proceeded to jams the Headblasters into Omega Zero's head, firing repeatedly until the circuitry in Omega Zero was exceedingly damaged. Monolith then quickly pried open his head and tore out wire after wire in a desperate attempt to disable Omega Zero, and finally managed to connect with his core. Created a barrier around the both of them, Touma and Monolith were blown backwards in a large blue explosion created once Monolith shot Omega Zero's core.

Omega Zero had been defeated at great cost.

Aftermath
Immediately following the incident, Monolith fled the scene alongside the soldiers. Before doing so, Touma begged for Index to be saved similar to how his hand had been repaired. Monolith explained that was only possible because Touma was alive and his hand was intact. While it was possible for Monolith to save Index's life, use of the ability to do so had to be used in a controlled environment to avoid ripping reality apart, and thus Monolith refused.

Before leaving, Touma asked why they even landed here to fight if Monolith could have fought anywhere. Monolith briefly admitted that being here was an accident, but said "these things sometimes happen".

Touma would eventually learn that Monolith had engaged Omega Zero in an attempt to kill him once-and-for-all, but wasn't positive it would succeed... it did not. Omega Zero awoke prematurely, but was still a force to be reckoned with, and over the course of nearly an hour, two barren planets had been entirely destroyed, and four solar-systems had also been blown to pieces by Omega Zero. The next destination was essentially an accident, however, the situation was avoidable.

Fighting Omega Zero is risky, and more time could have been spent preparing for the fight. Because Monolith attempted it so quickly and without proper equipment or backup, the situation quickly flew out of hand once Monolith could no longer control the situation. Had Monolith waited, the deaths that happened could have been mostly or entirely avoided.

It was this detail in particular that angered Touma enough to begin his quest to take down Monolith for the destruction of Academy City and the death of his friend. Additionally, Misaka never found her friend, and eventually left Academy City to live with family.

In total, around 400,000 people survived, many with extreme burns, and many with these burns died over the course of the next several days either in hospital care or amongst the piles of corpses in Academy City's wake. Almost every student had been killed due to the population density at the school festivals, and most government officials were killed as well. None of the buildings stood a chance, and anything in the path of the Barrier Crash simply burned away or was blown clear off its foundation. In total, sixty five government laboratories were found in the wake of the destruction, all demolished so badly that it was nearly impossible to discern exactly what they had experimented on to begin with.

A vigil was held for the 1.8 million deaths, and the 22,000 survivors who escaped with minimal or no injuries left the city to live elsewhere and never return. Academy City was slated to be rebuilt, but the sheer cost exceeded nearly 6 quintillion dollars. So much sensitive equipment, loss of personnel, demolition of infrastructure, contamination of the surrounding area by unknown toxic particles created by Omega Zero's attacks, and general cleanup, exceeded numbers beyond expectation. Ultimately, it is still being rebuilt, but the process is slow and painstaking.

The official record on the planet was the surprise appearing of a Level 6 esper, a concept so far heard of only in theory and legend, but never realized. Some condemned the city officials, however anyone in power was killed in the attack, and those who hadn't died went underground to avoid stigma and prosecution.

Touma would also learn a couple years later at a small restaurant on the planet Korhal that the incident was publicly considered to be a great success on Monolith's part, with Monolith heading a large moment of silence for the deceased and making a public conference in which it was explained that Monolith had chased Omega Zero, who had been leaping from planet to planet in an effort to destroy everything. As Touma knew these were lies, he attempted to explain the truth to some who would listen, but nobody was willing to believe that the situation was born of Monolith's ineptitude and instead bought the public version: Monolith was a hero who saved the universe was potential destruction by bravely defeated Omega Zero all alone.

Alternate History
According to the Colette, the Zero Index Incident was far more successful in her home dimension and resulted in 99.98% less casualties with only three million in damages compared to the six quintillion damages done on the planet that rendered Academy City little more than a mass grave.

While the attack was also highly irresponsible, the first priority of Subjugation was to evacuate the city and set up shield barriers as Colette had already been told it was likely Omega Zero would end up in this location if he moved in a straight line. While the fight did end up in this city, deaths and damage were mostly due to lack of time rather than straight negligence.

The battle still ended with Touma's friend, Index, being ultimately beheaded by Omega Zero, and with a halfhearted apology, but Touma's reaction apparently well significantly beyond acceptable responses as Touma eventually met with that version of Dark Mega and nearly destroyed half of the universe in an event that the Colette refers to as the Universal Index Remodel. These actions ultimately branded this version of Touma Kamijou as a villain.