Yokai

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

- Fred Professor Robert 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 and mentor of Tadashi Hamada. However, after a tragic incident, he became the villainous Yokai, determined to extract revenge on those who wronged him.

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 whom he valued more than anyone or anything. Abigail 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 "Project: 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 vengeance on Krei, eventually descending into villainous madness as time would pass and his lust for revenge strengthened.

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. Above all, his only true love and concern was Abigail, referring to her as his "everything", and valuing her above all others. 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 uncaring man, bent on seeking revenge on the ones who wronged him, willing to kill anyone who gets in his way, even slightly. With Abigail's demise, Callaghan'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 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, though all with no remorse.

This makes Yokai one of the most ruthless of the Disney villains, though at the same time, he is also one of the most sympathetic. Unlike other villains, whose ambitions 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 death of his daughter; the person he loved most. Callaghan is also one of the more complex villains, sharing this complexity with Hiro. At certain points in the film, 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, however, Callaghan makes an interesting, rather penitent expression. By the look of his face, one could assume he regrets his actions, whilst his ultimately merciless nature, firmly caring for his daughter only, heavily implies that his look of despair is centered around the high possibility that his arrest and near-apocalyptic actions will lead to life in prison, thus permanently separating him from his only loved one, whom he worked immensely to avenge, finally realizing the consequences of his actions and the emptiness of revenge. All these factors make Yokai one of the most three-dimensional Disney villains.'

In short, while Callaghan is ruthless and relentless in his pursuit of revenge, he is not incapable of feeling remorse when it was for nothing.

Physical appearance
Robert Callaghan is a tall, somewhat elderly 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 San Fransokyo Institution of Technology. 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 covered by a red and white kabuki mask, which acted as his ultimate source of power and control over the Microbots. 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.

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 accidental interference of Baymax, Tadashi's healthcare robot, Yokai's plot would have very well succeeded.

Role in the film
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 massive 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 Yokai. With the Microbots under his control, Yokai spends a period of time multiplying the Microbots and creating an overwhelming army, enabling him with incredible strength, agility, and making him a near unstoppable force. One day, Hiro and his robot companion, Baymax, accidentally comes across Yokai's warehouse, where they find the Microbots. Noticing this, Yokai attacks the duo, though they manage to escape in the nick of time.

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 massive piece of technology at hand (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 power as, without it, he'll be unable to control the Microbots.

After many failed attempts, Hiro manages to accidentally remove 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 out of the professor's own selfish gain, Hiro explains the circumstances of Tadashi's demise, and how the latter died trying to save the professor, only for Callaghan to coldly claim him 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 and unable to perform violent acts on human beings, Hiro removes the bot's healthcare chip, leaving only his battle-centric programming within his system, 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, knowing murder would be the wrong choice, as revenge is a hollow victory. Nevertheless, Baymax continues to attack, and 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 and revealing his true identity, much to Krei's shock. The tech-guru pleads for mercy, but the former professor instead takes the time to confront his enemy on his daughter's death. There, Callaghan announces his plot to use the newly built portal to destroy everything Krei's built (which would inevitably lead to the destruction of the entire city), before killing Krei himself. Without further ado, the portal is recreated on the spot, right above Krei's headquarters, and the massive destruction begins. Just then, Big Hero 6 arrives on the scene. Hiro tries to talk some sense into Callaghan, explaining that Abigail wouldn't approve of his actions, along with the fact that revenge is a hollow victory and won't make things better. Though Hiro's words throw Callaghan into a state of thought, the villain soon allows his bitterness and hatred to consume him, once again, and ultimately makes the decision to kill everyone on the battle ground, initially paying the most attention to Baymax. Using the Microbots, Callaghan manages to pin down every member of the team, leaving them to face slow, and painful deaths.

Meanwhile, the portal continues its massive chaos, nearly sucking in Hiro, as well. Fortunately, Baymax sees this and breaks free of his metallic prison, rushing to Hiro's rescue. The young boy genius then instructs his team to do what they can to send the Microbots within the sucking portal in hopes of subduing Callaghan's power, whilst he and Baymax distract the villain, themselves. The plan is set in motion, and whilst Go Go, Wasabi, Fred, and Honey Lemon carry out the breakthrough from below, Hiro and Baymax take on Callaghan, personally.

With his focus and frustration solely on Hiro and Baymax, Callaghan fails to realize his army of Microbots rapidly declining due to the efforts of the other team members. Losing his patience, Callaghan finally manages to capture the boy and his robot and prepares to make the killing strike, only to find that he has run out of the remaining available Microbots, thus rendering him powerless and vulnerable. With this, Hiro and Baymax break free of their confinement and thrusts towards the masked villain. Callaghan fearfully prepares for his oncoming demise, but instead, Hiro and Baymax decide to spare his life, explaining they refuse to harm a human being, despite the damage he's caused. With that, Hiro and Baymax take Callaghan's mask and smash it into smithereens, thus eliminating his remaining Microbots and subduing the portal. Having lost control of the Microbots, Callaghan almost gets sucked into the portal, but Baymax grabs him and brings him safely down to the ground.

However, as a result of the battle, the destruction causes the portal to become unstable, and on the verge of exploding, prompting everyone to retreat. Baymax, however, stays behind, sensing life within the portal, and revealing the victim to be a female in hyper-sleep. Hiro assumes 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. Though Baymax is destroyed in the process, 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, feeling regretful of the atrocious, near-apocalyptic actions he has committed, manages to see his daughter one last time and hangs his head down defeatedly at the realization of being separated from her once again.

Trivia

 * Yokai (妖怪) means "spirit" or "phantom" in Japanese.
 * Even though he makes multiple appearences as Yokai, his name is never mentioned in the movie, usually being 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 suffers a tragic loss of a loved one. This leads both Callaghan and Hiro on a dark path, driven by a lust for vengeance and the murder of 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, Callaghan expressed regret after seeing that his plan for revenge had 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, the entity that is Yokai apparently symbolizes 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).
 * 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 didn't hesitate to make several attempts at their lives throughout the film.
 * There is an error in the film involving him: 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. It could be possible Callaghan saw Tadashi before the showcase hall exploded and refused to take the time to save him, or he could have simply caught word of Tadashi's death and the circumstances of his demise during the events leading up to his confrontation with Hiro.
 * According to character designer, Shiyoon Kim, Callaghan has a military background. This would explain his well-built physique, and possibly, his choleric nature.