Yokai

"That mask... The black suit; we're under attack from a super villain, people!"

- Fred Professor Callaghan (also known as Yokai) is the main antagonist of Disney's 2014 animated feature film, Big Hero 6. He was the head of the San Fransokyo Institute of Technology's robotics department, and mentor of Tadashi Hamada. He assumes the identity of Yokai after a tragedy drives him to become a malefactor bent on personal vengeance.

Background
"He was such a good man... What happened?"

- Honey Lemon

Professor Callaghan was an aspiring man; a world-renowned scientist, praised for his innovations on the foundations of robotics, as well as the creation of Callaghan's Laws of Robotics. With such recognition and knowledge, Callaghan put himself to good use by teaching as the head professor at the San Fransokyo Institution of Technology, where he mentored such prodigies as the brilliant Tadashi Hamada, who admired him greatly. Notably, though he was passionate about science and robotics, Callaghan's true love lay within his daughter, Abigail, who was once a test pilot for Krei Tech Industries: the world's leading technology industry, owned and operated by San Fransokyo's own Alistair Krei. One of Krei's latest ambitions, at the time, was the desire to revolutionize transportation through the use of portals—a project dubbed "Silent Sparrow". Unfortunately, during the experimental test run, a malfunction occurred in the system, and Abigail was lost in the portal, eventually presumed to be deceased. The tragedy left Callaghan with a hardened heart, and since, he swore revenge on Krei, eventually descending into villainous madness as time would pass and his lust for vengeance strengthened. This would ultimately lead to the abandonment of Callaghan's former identity, and the birth of Yokai.

Official Description

 * Professor Robert Callaghan heads up the robotics program at the prestigious San Fransokyo Institute of Technology and is Tadashi’s professor and mentor. When Hiro visits the university for the first time, he is star-struck by the world-renowned roboticist—while Callaghan immediately sees the potential in the 14-year-old prodigy, encouraging him to put his brain to better use.


 * Yokai is the silent masked man behind the terrible tragedy that strikes San Fransokyo, turning Hiro’s world upside down. As a result, Hiro transforms a group of nerds into a team of high-tech crime fighters—Big Hero 6—with one mission: Track down Yokai and bring him to justice.

Personality
"What makes Marvel villains interesting is that they are righteous. They think they are doing the right thing, or at least the necessary thing, which makes them more human and relatable. Yokai is not a villain in his own mind."

- Tech supervisor Hank Driskill

Before the tragic incident involving his daughter, Callaghan was apparently a good-hearted, loving man, bent on changing the world for the better through the wonders of science and technology. He presented himself as a humble figure, with the wisdom to guide young minds down a bright path, in addition to serving as a father-figure to his students; specifically towards Tadashi. He was also passionate about the subject of science, and resented those who used such technological advances for selfish gain, such as the pursuit of wealth and vain recognition, as opposed to improving the world. Above all, however, his true love and concern was Abigail, whom he referred to at one point as his "everything". It was her supposed death and Krei's ignorance towards innovation that led Callaghan down a dark path, eventually becoming a murderous, vicious, ruthless and somewhat uncaring man, bent on seeking revenge on the ones who wronged him and willing to kill anyone who gets in his way, even slightly. With Abigail's demise, Yokai's morality seemed to have vanished, and his lengths to achieve vengeance had no bounds, as he continuously made attempts to kill Hiro and his other students (originally due to the fact that they were witnesses, and later as a result of them being a significant threat to his plans), in addition to performing acts such as rampaging through the streets, destroying parts of the city, and continuously endangering innocent lives to the point of indirectly killing his own prodigy, Tadashi, all with apparently no remorse.

Callaghan also seemed to have abandoned his own personal code of respecting science. Once he got his hands on the Microbots, he immediately used them for his own selfish gain, in addition to repeatedly utilizing them as a weapon of mass destruction and homicide, despite their initial purpose being to further the well-being of humanity. Signs of arrogance can also be seen through his actions, as his lengthy list of crimes have been apparently met with little, to no remorse, as he viewed his mission to kill Krei and avenge Abigail as more significant than the lives of the innocent. When first introduced to the concept of the Microbots, Callaghan watches intently with a smug expression, which has been noted to distinctly represent his confidence and joy over the fact that Krei will soon meet a brutal demise at his hands. Despite his arrogance, Yokai knew his power was limited to the strength of the Microbots, and when that was stripped away from him, he became visibly fearful and submissive. Aside from brief moments of indecision, these were notably the only instances in which Yokai showed any sort of vulnerability.

According to Baymax's scans, Yokai is mentally ill, suffering from acute stress disorder, as well as emotional instability, as a result of his tragic past. This likely plays into his villainy, as he spends a majority of the film in a deep state of either anger, or sorrow, which prompts almost immediate rage, and murderous actions when triggered. Even so, Callaghan is highly capable of concealing his true emotions, as he presented himself as humble, level-headed and collected during his moments at San Fransokyo Tech early in the film, prior to the birth of Yokai, and was evidently viewed as such by those around him. Even after becoming Yokai, he generally remained stoic in the midst of his villainy, carrying out his schemes in haunting silence, and even remained in such a state during battles.

Ultimately, Yokai is one of the most ruthless, and dangerous of all Disney villains, though at the same time, he is also one of the most sympathetic. Unlike other villains, whose actions are driven through a lust for power and recognition, Yokai is not a villain in his own mind, as his schemes were motivated by the supposed death of his daughter; the person he loved most. Yokai is also one of the more complex villains, emotionally; at certain points in the film, most notably just before the final battle ensued, he would fall into a state of morality and regret before returning to his plot, making him somewhat of an anti-villain. During his final scene, in fact, Callaghan makes an interesting, rather penitent expression, showing an understanding of the consequences of his actions and the emptiness of revenge.

In short, while Yokai is undeniably ruthless and relentless in his pursuit of revenge, he is not incapable of realizing the damages caused by his actions, and facing moral dilemmas, such as remorse, making him one of the most human Disney villains.

Physical appearance
Robert Callaghan is a tall, middle-aged man with a generally warm appearance. With his gray hair, sweatervests, and slacks, he donned the appearance of a kindly grandfather; matching his relationship with his students at the institute. He also has somewhat wrinkled skin, that's fair in color, with blue eyes, and a rather large nose.

However, throughout most of the film, even after his reveal, Callaghan mostly took the form of Yokai. As the masked villain, Callaghan was taller, darker, with a brooding appearance that gave off an ominous aura. His face was entirely covered by a kabuki mask, which was mostly colored in white, with red markings symbolizing his anger and hate. The eyes of the kabuki mask were colored a piercing yellow. He also wore a black trench coat, black gloves, leg wraps, and ankle-length ninja boots.

Powers and abilities
Yokai's primary source of power were Hiro's Microbots. With the transmitter created to gain control over the miniature robotic army, Yokai was able to transform the robots into a deadly force, capable of immensely dangerous acts. To control them, the headband of a transmitter was inserted within his kabuki mask, and without said mask, control over his Microbots would cease, thus rendering him powerless. Though he generally lacks physical strength, Yokai has been shown to have a considerable amount of physical attributions, as seen during the car chase through the San Fransokyo streets. Even so, such attributes weren't utilized in other scenes, as he heavily relied on his Microbots and own, personal cunning, to do away with his enemies.

The Microbots were capable of forming into anything the mind could conceive. When in battle, Yokai's typical course of action would be to form the Microbots into a giant, spear-like shape, which would swiftly strike at his enemies in hopes of impaling them. He would also use the strength of the Microbots to utilize surrounding objects heavy in weight to crush his enemies, such as a cargo container, a car, or a massive piece of concrete.

The Microbots could also be used as Yokai's source of transportation on multiple terrains, as they were capable of being used on both solid land, and sea. During travel, Yokai would usually stand at the high center of the Microbots, which would be formed into a mountainous form during such occasions.

It should also be noted that Yokai's secondary source of power was his own intellect. With such power over the mind, Yokai was able to carry out his plot to solely rebuild Krei's portal (which is an example of his vast intelligence, in and of itself), steal Hiro's Microbots, and duplicate said inventions without having law enforcements catch on. In fact, if it weren't for the unintentional interference of Baymax, Tadashi's healthcare robot, Yokai's plot would have very well succeeded.

Big Hero 6
Callaghan is first introduced at the San Fransokyo Institute of Technology, where he is introduced to Tadashi's younger brother, Hiro Hamada, a young genius. Tadashi reveals Callaghan is the renowned creator of the very technology Hiro uses for bot-fighting purposes, and the cunning professor subtly reprimands the boy's actions, cleverly convincing him to join the school alongside his brother, to use his brains for greater purposes. In order to gain acceptance, Hiro builds, what he calls, the Microbots, a robotic army of miniature bots capable of becoming anything the mind can conceive, through the use of a telepathic transmitter. Hiro takes his newfound invention to the school's annual student showcase, where several up and coming geniuses showcase their unique inventions in an attempt to receive acceptance into the university.

Hiro's Microbots immediately impress Callaghan, though they also catch the attention of Alistair Krei. Krei immediately expresses interest in purchasing Hiro's inventions, but because of their past history with one another, Callaghan intervenes, warning Hiro to steer clear of the tech-guru, as (according to Callaghan) he only uses the foundation of science for his own selfish gain. After some consideration, Hiro takes Callaghan's advice, and refuses to sell his creation. And with that, Callaghan grants Hiro acceptance into the school.

However, after Hiro's departure, Callaghan steals the Microbots for his own nefarious purposes in seeking revenge on Krei, and to cover his tracks, the professor sparks a huge and deadly fire, setting the showcase hall ablaze. As panicked attendants barely escape the disaster with their lives, Tadashi gets word that Callaghan is still within the building, and rushes inside to rescue him, losing his life in the process once the building violently explodes, and leaving Callaghan to be presumed dead. Unbeknownst to anyone, however, Callaghan used the Microbots to save himself, and proceeded with his plot to get revenge on Alistair, under the guise of a mysterious and elusive masked figure known as Yokai. Yokai sets up a base of operation within an abandoned warehouse near the city's harbor, where the Microbots are massed produced to create an overwhelming army. One day, Hiro and Tadashi's healthcare robot, Baymax, stumble upon the warehouse and discover the vast army of Microbots. Yokai notices their presence, and immediately uses the bots to attack, though the duo barely manage to escape.

Realizing the fire that killed Tadashi was no accident, and was merely used as a means to cover the tracks of the Microbot theft, Hiro transforms Baymax into a crime-fighting robot and heads out to the warehouse in the middle of the night in hopes of capturing Yokai and bringing him to justice. They use the only Microbot left in their possessions to track down the masked villain, leading them to the trading post. There, Yokai emerges from the foggy bay, with a piece to the dismantled Silent Sparrow portal, prompting Hiro and Baymax to take cover in silence. They remain hidden until Hiro's friends, and Yokai's former students (Honey Lemon, Wasabi, Fred, and Go Go Tomago) arrive, causing enough noise to catch Yokai's attention. Once spotted, the masked villain attacks the group, and makes an attempt to kill them, believing they've seen too much (according to Fred). Using the Microbots, Yokai rampages through the city, after the team's vehicle, making several attempts to destroy them before they can escape. Though Yokai's attempts nearly succeeds, the team eventually manages to evade him by accidentally driving their car into the sea and apparently drowning. Yokai looks upon the damage, and believes them to be dead, thus prompting him to depart.

However, the team survives and manages to return to dry land and safety. Afterwards, under the guidance of Hiro, they use their technological advances to become a superhero team known as Big Hero 6, with hopes of stopping Yokai's plot and saving the city. Meanwhile, Yokai continues onward with his revenge scheme of recollecting the missing pieces to the Silent Sparrow portal, and does so by infiltrating an abandoned facility on Akuma Island. Notably, the facility once belonged to Krei, and was the area in which both Silent Sparrow and Abigail's supposed death took place. Baymax is able to track the villain's whereabouts and the team heads over to the island for another battle. Before Yokai arrives, they find a recording that reveals what happened to Abigail. They also learn the incident resulted in the closure of Krei's facility. This leads the group to believe Krei is the man behind the mask, wanting to rebuild his portal. Just then, Yokai finds the team and attacks. A battle ensues, and each member tries to remove the mask, knowing the mask is the true source of Yokai's power.

After many failed attempts, Hiro manages to accidentally knock off the villain's mask, and Yokai's true identity is revealed to be Callaghan. A confused Hiro asks the circumstances of Callaghan's survival, and the latter reveals his use of the Microbots to shield himself from the flames and escape his own death. Saddened by the fact that Tadashi died for nothing, Hiro explains how the former died trying to save the professor, only for Callaghan to coldly claim Tadashi running into the burning building was his own mistake. Angered by these words, Hiro orders Baymax to kill Callaghan; though the robot denies at first, being a healthcare robot unable to perform violent acts on human beings, Hiro removes the bot's healthcare chip, leaving only his battle-centric programming within his system, thus turning him into a mindless killing machine. The vicious robot then proceeds to attack a powerless and fearful Callaghan, but fortunately for him, the other team members intervene to protect him, knowing murder is never the answer. In the midst of the chaos, Callaghan manages to retrieve his mask and flees the scene, along with the remaining piece of the portal.

The following day, Yokai intercepts Krei's latest ceremony, immediately capturing the tech-geru before revealing his true identity. Krei is briefly taken aback by Callaghan's appearance, having believed him to be dead, but his confusion is quickly replaced by pure fear as Callaghan confronts his nemesis on his daughter's demise, blaming Krei for the preventable tragedy, and announcing his plot to use the newly rebuilt Silent Sparrow portal to destroy all Krei has ever built, before killing Krei, himself. Krei pleads for mercy, but with Callaghan's mind set, the portal is activated, being held high above Krei's building by the Microbots. Just then, Hiro arrives alongside his teammates and confronts the former professor, demanding he call off his plot as Abigail wouldn't approve. When Callaghan argues against such claims, Hiro continues, explaining that revenge is a hollow victory, specifically with loss, having learned such a lesson through personal experience. Realizing what Hiro says may be true, Callaghan falls into a state of moral thought, only to be drawn back into a murderous state once Krei makes a sleazy attempt to escape the situation, igniting a deadly battle against Yokai and the Big Hero 6 team. Hiro orders his teammates to aim for the villain's mask, but Callaghan proves to be a nearly unstoppable force, and quickly imprisons each member of the team in a cluster of Microbots, leaving them to face slow and painful deaths. However, unknown to Callaghan, some of the Microbots are being sucked into the portal alongside Krei's building, giving Hiro an idea. After guiding his teammates to safety, Hiro gives the command to take out the Microbots; once broken apart, they will be sucked into the portal, thus leaving Callaghan with no source power. The plan is set in motion once Honey and Fred create a smokescreen surrounding the bottom half of Callaghan's Microbot tower, to cover up their actions, while Hiro and Baymax distract the villain from above. According to plan, Callaghan is oblivious to the actions of Honey, Wasabi, Go Go, and Fred, and his army of bots continues to decline as his focus and frustration are aimed entirely on Hiro and Baymax. Before long, the boy and his robot are both captured, and Callaghan prepares to make the killing strike, only to find that he has run out of the remaining Microbots, thus rendering him powerless and vulnerable. With their plan having succeeded, Hiro and Baymax break free of their confinement and thrust towards the masked villain. Callaghan fearfully prepares for his apparent demise, but instead of killing him, Hiro makes the decision to spare his life, explaining that he and Baymax refuse to harm a human being. Nevertheless, Baymax destroys Callaghan's mask, thus eliminating his remaining Microbots and descending the portal.

However, as a result of the battle, the destruction causes the portal to become unstable, and on the verge of exploding, prompting everyone to flee. Baymax, however, stays behind, sensing life within the portal, and revealing the victim to be a female in hyper-sleep. Hiro correctly deduces it to be Abigail and makes the decision to journey inside the mysterious void, alongside Baymax, to rescue her. Meanwhile, Callaghan stays behind (while being physically restricted by Fred) with the team members and Krei, awaiting Abigail's return as the destabilized portal continues to break apart. Hiro manages to bring Abigail to safety, and police and paramedics soon arrive onto the scene. A now conscious Abigail is wheeled towards a waiting ambulance, ignorant to the events or her father's actions and presence, while the police apprehend Callaghan for his crimes and shove him into the back of a patrol car. Before being taken into custody, Callaghan manages to see his daughter one last time from a distance, and subsequently hangs his head down, possibly out of remorse for his actions.

Cameos
Yokai's kabuki mask makes an appearance in the deleted Zootopia scene, "Detective Work", seen on a shelf in Officer Bob's office.

Disney INFINITY: 3.0 Edition
Yokai makes an appearance in the San Fransokyo circuit of the Toy Box Speedway feature, as a non-playable character. After the first lap, the Microbots begin attacking and taking control over the city, eventually revealing the Silent Sparrow portal looming over the city, as well as Yokai, who ominously watches as the racers pass by while standing atop a towering cluster of Microbots.

Disneyland Paris
On December 31, 2015, Yokai made his debut as a meet-and-greet character in the Disney theme parks during a private event held at Disneyland Paris.

Trivia

 * Yokai (妖怪) means "spirit" or "phantom" in Japanese.
 * Yokai bears a striking resemblance to the Marvel character Lord Deathstrike.
 * Callaghan's Yokai identity is never spoken in the film, usually referred to as the "Guy in the Kabuki Mask", "Masked Man", or the "Man in the Mask".
 * Callaghan serves as a dark parallel to Hiro. Both individuals are brilliant scientists, whom suffer a tragic loss of a loved one. This leads both Callaghan and Hiro on a dark path, driven by a lust for vengeance against those they deem responsible. Unlike Hiro, however, who eventually accepts his loss and finds the strength to move on, Callaghan fails to learn the errors of his destructive ways, ultimately leading to his descent into madness and downfall. With these factors, Callaghan is an example of what Hiro would have become, if the latter had allowed his anger and despair to consume him.
 * Interestingly however, both express regret for what they had done. While Hiro expressed regret for nearly dishonoring his brother's memory in trying to kill Callaghan via Baymax, Callaghan's sad facial expression at the end strongly implies that he feels remorse for all his crimes after seeing that his plan for revenge had ultimately been for nothing, after seeing his daughter alive.
 * As mentioned above, Callaghan spends most of the movie under the guise of Yokai; even after his identity is revealed. From a storytelling perspective, Yokai represents Callaghan's dark side. Whenever the man shows a hint of morality throughout the film, the mask of Yokai is off; but when he allows his bitterness and hatred to take control, the mask returns and villainy ensues.
 * Though Tadashi's death was ultimately an accident, Yokai is one of the few Disney villains to permanently kill off a major character in their respective film.
 * His name may have originally been Dr. Martin Lebur according to the 2013 Rotoscopers video and early information. As Lebur, Callaghan was not a big fan of Hiro's intelligence, though this may have been changed to prevent any dead giveaways to his identity.
 * Originally, during the early stages of the film's development, Yokai was the leader of a nefarious gang, having aligned himself with a legion of San Fransokyo's criminals to assist in his plot. The group of henchmen included deleted villains such as the Fujitas, Mr. Sparkles, and the Bonsai Bombers (as seen in the Art of Big Hero 6 book).
 * In one of the first drafts of the script, Yokai would have been Alistair Krei, who would have become Yokai in order to create a menace to the city, so he could promote a defense project he created. He would have brainwashed and used Professor Callaghan and Tadashi, who would have survived the explosion as scape goats. This idea was scraped as the production team felt that Krei being the villain would not have enough impact on the story and would be too obvious.
 * Though he lacks a musical number, Yokai has a recurring, instrumental theme that plays throughout most of his scenes.
 * Yokai never speaks until after his identity is revealed.
 * According to Baymax's scan, his blood type is AB- and he weighs 173 pounds (78 kg). Diagnosis: Acute stress disorder, High risk of cardiovascular disease & Emotional instability.
 * Because of his treatment towards his former students and Tadashi, following the Microbot theft and birth of Yokai, it is unknown as to whether or not Callaghan actually cared for the students of San Fransokyo Tech, as he expressed no remorse over his part in Tadashi's demise, nor did he show any hesitation in making multiple attempts to kill Hiro and his friends throughout the film.
 * When first introduced, Callaghan is wearing a blue shirt, but when he raises his hand out for a moment to see Hiro's bot, his shirt is red.
 * The red markings on Yokai's mask symbolize anger.
 * Interstingly, according to Big Hero 6: The Junior Novelization, Callaghan was the last person Tadashi saw before the latter's death.
 * Notably, during Hiro and Callaghan's confrontation following the reveal of Yokai's identity, Hiro states "But, Tadashi... You just let him die!" and Callaghan never denies these words, only responding by revealing he knew of Tadashi's sacrifice.
 * According to character designer, Shiyoon Kim, Callaghan has a military background.