Yokai

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.

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, 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 lied within his daughter, Abigail whom he valued more than anyone or anything. Abigail was notably a test pilot for Krei Tech; 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. 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.

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 tragic. 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. 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.

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.

Role the flim
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 science fair, 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 extract 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, 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 and the group becomes the villain's target. 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, 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 by recreating one of Krei's portals in an abandoned facility on Akuma Island. 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 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 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 reveal he feels total apathy for his murderous actions, and angrily blames Tadashi for his own death, coldly claiming him running into the burning building was his own mistake. Torn by these words, Hiro orders Baymax to kill Callaghan, much to the latter's shock and horror. 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 mix of the chaos, Callaghan manages to retrieve his mask of power 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 completed 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 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 brief, as Callaghan, once again, allows his bitterness and hatred to consume him, 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 memeber 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 GoGo, 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 himself powerless and vulnerable, with all of his Microbots having been terminated and sent into the portal. 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.

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, whilst the police apprehend Callaghan, who sees his daughter one last time, from a distance, being taken into custody.