Kamijou Touma/Imagine Breaker

The Imagine Breaker (幻想殺し (イマジンブレイカー)) is the mysterious power that resides exclusively within Kamijou Touma's right hand, allowing him to negate anything supernatural such as esper powers, magic powers, and even to his own admittance God's miracles.

Neither magic nor esper ability, the Imagine Breaker has long been under intense speculation both in-universe and in the fandom, with only a few people in-universe such as Aleister Crowley knowing fully of what it entails.

Etymology
Seemingly a reference to Touma's Imagine Breaker, Touma incorporates the meaning of the kanji used for his ability (幻想殺し), which means Illusion killer, into his famous catchphrase which can be translated into English as: "I will kill that illusion of yours."

Interestingly in the novels, the kanji for the Imagine Breaker is sometimes changed to Ore no Migite (俺の右手).

Primary features
Shown throughout the series, Touma's Imagine Breaker, negates both esper powers and magic. Moreover, through several circumstances, even divine powers, such as, in his own admission, the miracles of god, and more prominently his defeating of Archangel Gabriel in World War III. Furthermore, the narration even states that Touma's power can kill even God.

Supplementary features
In two different instances, Touma demonstrated that he can dispel to an extent the effects of an area-wide attack. One instance is blocking the effects of electricity Misaka Mikoto created, by putting his right hand out to act as a lightning rod for the electricity to be directed to his right hand and Imagine Breaker as opposed to another part of his body without the Imagine Breaker's protection. The other one is blocking a portion of Kaitabi Hatsuya's Graviton from hitting the people behind him using Imagine Breaker as a shield. Nonetheless, it is required for him to have physical contact to initiate the effects of his power.

It seems that Imagine Breaker has a permanent cancelling effect on some supernatural objects, as seen when it robbed Index's clothes of their Walking Church. As for the case living beings, the effect seems to last for as long as Touma has a solid grip on them with his right hand, and that if he releases them from his hand's grasp, they immediately regain their power almost instantaneously.

Imagine Breaker can even ignore the overall actual weight or force behind of which an inanimate object has supernatural power concentrated on, as seen when Touma blocked a full-powered punch from a massive golem without showing signs of obvious effort, before the golem collapsed on itself due to the magic that manifested it being abolished by Imagine Breaker's power. He did, however; "almost break his hand" in said exchange.

Weaknesses and Limitations
Despite of the extents of Touma's abilities, Touma might not have the ability to negate all "artificial" supernatural abilities, such as the Power of the World and leylines. Some objects such as the Queen's Fleet and Innocentius require Touma to target the core or some other important piece that provides power to them in order for his Imagine Breaker to effectively negate them.

Also, since the Imagine Breaker is concentrated to only Touma's right hand, Touma is truly helpless against a wave of magic attacks in great numbers, as what happened with Misawa Cram School and the Gregorian Chant Replica performed on him. Furthermore, since the effects of Touma's Imagine Breaker is always singular, as in it can only negate, magicians such as Oriana Thomson can make use of this to make a trap against Touma after negating a spell.

So far there are only a few attacks which can "surpass" Kamijou Touma's Imagine Breaker power canceling speed, as such he is unable to completely destroy them despite continued exposure to the Imagine Breaker. Index's Dragon Breath, Stiyl's Innocentius , Fiamma's flaming sword , and Accelerator's wings in his awakened state. The Curtana Original's Dimensional Cleavage Formula is a different case, as it does not fall under the 'surpassing cancelling speed' category, but 'After this window of opportunity it can't be negated' category. It would imply that the phenomenon that Curtana had brought upon have become normalized and is no longer considered a supernatural phenomena. Kanzaki stated Imagine Breaker can negate a dimensional cutter attack if it comes into contact within 1.25 seconds.

During his trip to Russia, Touma makes use of the Imagine Breaker's limitations. Due to Imagine Breaker not fully negating supernatural phenomena, Touma has learned to use the Imagine Breaker to interfere via "negation and disruption". Touma made use of this when he battles Accelerator in Russia. Normally, Imagine Breaker negates any supernatural power or object upon contact, but because of its limits, if a supernatural power/object is sufficiently powerful or massive enough in size it will not be completely negated right away as it will take a longer time to fully defeat. It's during this state of cancellation that Touma can actually physically touch or grab the power/object, negating and disrupting it instead of instantly destroying or completely ridding of it right away. This, of course, is usually more of a disadvantage than an advantage of Imagine Breaker. Still, during Touma's fight with Accelerator in Russia, Touma pulled one of Accelerator's black wings to throw Accelerator off balance and dodge the attack when Accelerator struck Touma with 100 wings that he summoned. That single touch was capable of negating the vector controlling power of said wing as well.

Finally, according to Index's speculation, Imagine Breaker negates God's blessings, which is the luck people have, as is the reason why Touma is misfortunate, much to his horror. Furthermore, she speculates that his Imagine Breaker may also negate the red string of fate, which would also explain why girls gather around him without effort.

Effects on natural forces
The Imagine Breaker, however, is unable to negate the Power of the World, its ley lines, the lifeforces and souls of human beings, due to them being natural, despite being supernatural as well. According to Leivinia Birdway this is because the Imagine Breaker normalizes things that are of abnormal values, specifically, it destroys things that have had their harmony taken. However, things such as the aforementioned examples, have always been uniform from the start despite being supernatural in nature. Touma's Imagine Breaker can only destroy things that had their harmony's taken from them, as such something that had been abnormal from the start, such as the power of the world will never not be negated by the Imagine Breaker. Furthermore, Leivinia states that a cycle was probably set up from the start to be like that, and not how much the world can replenish power.

Effects on angels and divine beings
Imagine Breaker also seems capable of affecting an angel, since Archangel Gabriel who became Misha using Sasha Croitsef's body didn't dare to try and touch Touma's right hand when he offered her candy. Kazakiri Hyouka, the artificial angel, is subconsciously afraid of physically touching Touma. Furthermore, as a reaction to the Imagine Breaker, Hyouka gains a consciousness and is born within the Imaginary Number District. However, Touma cannot apparently completely negate them with the Imagine Breaker, as it's been shown that an angelic being has a core, which require it's destruction to be properly destroyed. Such as the rectangual prism within Hyouka's head or of the AIM Burst's. Archangel Gabriel too also returned to its realm upon coming into contact with Touma's Imagine Breaker near the end of World War III.

It is unknown what effects Touma's Imagine Breaker could have on other supernatural being such as Aiwass, though it can be assumed that since he also has a core, the effects of Imagine Breaker on him still applies.

Science side
Touma's status as a esper is a mere technicality, since he is enrolled in Academy City. Touma's Imagine Breaker could not be detected or classified by their machines, and just classfied Touma as a Level 0. As such Aleister Crowley considers him neither a esper nor a magician but rather a normal person with a unique ability. This allows Touma's actions to have a little leeway, since he is neither a magician nor an esper, he can interfere in various magic side business without implicating Academy City for directly interfering with magic side matters, such as what has occurred during the invasion of Misawa Cram School by Aureolus Izzard. Even Aleister Crowley seems to take advantage of this, allowing Touma do go into dangerous situations regardless of sides for his plans.

Most of the science side however, is unaware or plainly ignorant of the existence of the Imagine Breaker, and certain members of the general population, such as Saten Ruiko consider the existence of a person who has an ability that negate other abilities as an interesting urban legend.

This is also apparent in the dark side of Academy City, as only a few people such as Girl in dress, Kinuhata Saiai, and Tsuchimikado Motoharu, are aware of Touma's importance to Aleister Crowley, depite not knowing how exactly he fits into his plans.

Magic side
In the Christian dominations of the magic side, especially the Roman Catholic Church, the Imagine Breaker is considered a heretical power as it denies the blessings of God. In the most extreme cases, Touma himself is considered the heretic himself for having that power, although him being presently active in many failed Roman Catholic missions did not help his case. His heretical nature would later inevitably spark the invasion of Academy City, and later World War III.

After the end of the third world war, Touma has become a major target by magicians, and some, such as the masterminds behind Radiosonde Castle has even gone out of their way to endager the entire world just so to kill him.

Speculation and important points
The true nature of Kamijou Touma and the Imagine Breaker has yet have been revealed. Seemingly, only a few number persons know something about the Imagine Breaker. Terra of the Left for example, deduced Touma having amnesia since he is apparently not using the Imagine Breaker to its full capacity, and hints that Imagine Breaker might actually be an ability that might extend itself further away from its bearer's right hand, based on Terra's personal knowledge of Fiamma of the Right's Holy Right ability.

But the most obvious example is Aleister Crowley's interest in Kamijou Touma and the Imagine Breaker, having been implied to deliberately send Touma to dangerous situations since his introduction, have implied to have deliberately set up his meeting with Kazakiri Hyouka, as well as having implied at manipulating Touma to confront Oriana Thomson.

Touma and the Imagine Breaker's importance is later brought into further light, as he is considered the core of Aleister Crowley's plan alongside Accelerator, with his actions within the error range of Aleister Crowley, implying anything that Touma may do can probably become beneficial to his plans. In fact, the Imagine Breaker was apparently affecting 98% of Aleister's plans before the start of Carissa's civil war.

Furthermore, Touma is so important that he is referred to as the esper whose great value even among every esper in Academy City. His retrieval back to Academy City was to keep him alive at all cost during retrieval, although, if he sided with an organization he was to be attacked and later be kept with the same life support system used for Kakine Teitoku.

His importance is further emphasized as even Aiwass has taken an interest in him, alongside Accelerator and Hamazura Shiage.

Beyond the right hand
It has been hinted even from the very beginning that Touma's Imagine Breaker has a queer connection with dragons, with Touma's Imagine Breaker being able to destroy the Walking Church, that supposedly could only be destroyed if the Dragon that St. George would descend again. Strangely, Touma later does battle with both St. George's Sanctuary and Dragon's Breath in the same value, being unable to completely negate it and requiring Stiyl Magnus and Kanzaki Kaori's assistance.

However, the most striking example of this is in the climax of the Deep Blood Arc. Wherein after Touma had his entire right arm cut off, Touma uses Aureolus Izzard's Ars Magna against him using fear, which made Aureolus conjure up the dragon (referred as the Dragon King in its first appearance) that was used to defeat him. It is later hinted that Aureolus may not have been the one to come up with imagining Touma's arm to be replaced by a dragon.

The presence of something beyond the Imagine Breaker in Touma's right hand is not addressed again until the climax of the third world war. When Fiamma severed Touma's right arm along with the Imagine Breaker in order to absorb that power into himself, it was not for the Imagine Breaker ability, but for it to act as a medium for his Holy Right to gain a corporeal form.

Immediately afterwards, a "invisible thing" gathered on Touma's right shoulder which made all Fiamma has pale in comparison, but Touma unexpectedly crushed that power with an even greater power and then took back the Imagine Breaker. Though the true nature of those powers is unclear, Touma is shown to be able to communicate with "invisible thing" referring the power as "you" before refusing to use its power, crushing the power and regenerating his lost right arm.

After Fiamma's right arm was severed by Aleister, it was confirmed there is more to Touma's right hand than just a "a right hand that can negate supernatural ability". Touma's right hand is a vessel that can be used to house a greater power, and this is the main reason why Aleister and Fiamma seeks Touma's right hand, not for Imagine Breaker. Due to Fiamma's discovery of something within Touma's right hand, Aleister is forced to make an appearance into the world, hinting on how he knew what was inside Touma all along and now that Fiamma knew of its existence forces Aleister to eliminate Fiamma by his own hands. Although Aleister failed killing in Fiamma of the Right, it showed how important the Imagine Breaker and especially the unknown power residing in Touma's right hand to Aleister's plans that he is willing to show himself to the world and ruin his ruse of him being dead to the world.

However, the most important aspect of this is that Touma now also knows that something resides in his right hand.

Trivia

 * A very specific and high pitched sound is played in nearly every moment where Touma's Imagine Breaker negates something in both seasons of the Toaru Majutsu no Index anime adaptation.
 * The song Gensō Goroshi is present in the 2nd Toaru Majutsu no Index original soundtrack, and is name after Touma's ability. It is used in all animated adaptations of the franchise, both Railgun and Index, and is played often during moments of building towards action sequences. On the same soundtrack the song, Breakthrough can be found, having a faster tempo than the former and having a heavier rock-oriented arrangement.