Yokai



Robert Callaghan (also known as Yokai) is the main antagonist of Disney's 2014 animated feature film Big Hero 6. He is the head of the San Fransokyo Institute of Technology and was Tadashi and his friends’s professor and mentor. However, after a tragic incident, he becomes the villainous Yokai, determined to take revenge on those who wronged him. He is voiced by James Cromwell.

Background
Professor Callaghan was an aspiring man; a world-renowned scientist, praised for his innovations on the foundations 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. Notably, though he was passionate about science and robotics, Callaghan's true love lied within his daughter, Abigail whom he valued more than anyone or anything. After an accident at the hands of Alistair Krei, Abigail vanished off the face of the earth, 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 Disney Bio

 * 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
Before the tragic incident involving his daughter, Callaghan was apparently a good-hearted, loving man, bent of changing the world for the better through the wonders of science and technology. 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 her 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, believing them to be a threat in his plans. He was also willing to endanger the entire city, as his newly created portal caused massive damaged, endangering several civilians, though he didn't seem to care. Callaghan's madness was also shown during his confrontation with Hiro, where the boy explained Tadashi died trying to save him, only to have the villain retort by blaming Tadashi for his own death, ultimately revealing he cared nothing for the young man's innocent life.

All these factors 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's schemes were motivated by the death of his daughter; the person he loved most. At one point, during the final battle, he even showed a hint of regret, seemingly planning to call off his plot, only to immediately return to his dark nature once he allows his hatred to grow, thus proceeding with his scheme of killing Krei, and willingly giving the same deadly fates to his former students.

Role in the film
Callaghan is fist 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 science fair, were 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-geru, as 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. Meanwhile, Tadashi rushes into the burning building to save the professor, 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 extract revenge on Alistair, under the guise of Yokai. With the Microbots under his control, Callaghan 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, a healthcare robot named 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 in 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 docks. There, Yokai emerges from a fog, with a massive piece of technology at hand, 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 GoGo 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, driving their car into the sea and apparently drowning. Yokai looks upon the damage, and believes them to be dead and 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 by recreating one of Krei's portals in an abandoned facility on a remote island off the shores of San Fransokyo. Notably, the facility once belonged to Krei, and was the area in which Abigail was supposedly killed. 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 members 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 masked, Yokai's true identity is revealed to be Callaghan.

A confused Hiro asks the circumstances of Callaghan's, and the latter reveals his use of the Microbots to escape his own death. Saddened by the fact that Tadashi died out of the professor's own selfish gain, Hiro explains that Tadashi died trying to save him, only for Callaghan to reveal the fact that he not only knew of Tadashi's death, but fails to care, claiming the young man's demise was his own fault. Torn 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 boy'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. Fortunately, for him, the other team members intervenes, believing killing Callaghan to be the wrong choice, despite his actions, as revenge is a hallow victory. Nevertheless, Baymax continues to attack, and in the mix of the chaos, Callaghan manages to retrieve his mask of power, and flees the scene.

The following day, Yokai intercepts Krei's latest ceremony, immediately capturing the tech-geru and reveling 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 loves, before killing Krei himself. Just then, Big Hero 6 arrives on the spot. Hiro tries to talk some sense into Callaghan, explaining the fact that revenge is a hollow victory and won't make things better. Still, Callaghan ignores the boy's words, only to fall into a state of moral thought once Hiro acknowledges Abigail, knowing she wouldn't approve of her father's actions. Unfortunately, the state of thought is breif, as Callaghan, once again, allows his bitterness and hatred to consume him, and ultimately makes the decision to kill everyone on the battle ground. Using the Microbots, Callaghan manages to pin down every member of the Big Hero 6 team, whilst he takes on Baymax personally. Meanwhile, the portal begins its massive destruction, 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 gains the idea to have the team destroy the Microbots from below, whilst he and Baymax battle Callaghan, personally.

The plan is set in motion, and whilst GoGo, Wasabi, Fred, and Honey Lemon carry out the breakthrough from below, Hiro and Baymax battle Callaghan from above, craftily tricking him into shooting most of his Microbots into the sucking portal. Just as he's prepared to make the killing strike, Callaghan finds himself powerless, and his Microbots ultimately destroyed. As such, Callaghan is apprehended, and the portal is subdued. However, the destruction causes it to become unstable, and on the verge of exploding, promoting everyone to retreat. Baymax, however, stays behind, sensing life within the portal. Both Callaghan and Hiro assume it to be Abigail, and the latter journeys inside the machine to rescue her. Though Baymax is destroyed in the process, Hiro manages to bring Abigail to safety, and the authorities and paramedics soon arrive. A now conscious Abigail is taken to the hospital, ignorant to the events or her father's actions and presence, whilst the police apprehend Callaghan, who sees his daughter one last time before being taken into custody.

Trivia

 * During his final scene, Callaghan makes an interesting expression. By the look of his face, one could assume he regrets his actions, whilst his ultimately selfish nature, and concern for his daughter only, could imply that his look of despair could be out of the disappointment Abigail would surely have once she hears of her father's actions and downfall, leaving his ultimate thoughts on the events ambiguous.
 * Callaghan's appearance is similar to the main villain's of Atlantis: The Lost Empire, Lyle Tiberius Rourke. This is actually a subtle foreshadowing of him being Yokai's true identity.
 * His name may have been originally 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.
 * The Rotoscopers video also called for Yokai as having combined all of San Fransokyo's greatest criminals to do his dirty work (implied to be the Fujitas, Mr. Sparkle, the Bombshell Bombers and possibly Mr. Yama as shown in the Art of Big Hero 6 book). The said criminals were deleted from the final draft of the film, most likely because there was not enough screen time and opportunity to utilize them in a way that added any real value to the movie.
 * Yokai means "spirit" or "phantom" in Japanese.