Tao (Kor. 타오) is a Modified Human and a foil character of the series. He is an ex-member of DA-5 like Takeo. He switched allegiances, joining up with Rai and Frankenstein after finding out that the DA-5 group was actually created for Krantz to absorb their powers. He also convinces Takeo to leave the Union after telling him the truth. He currently works as a security official at Ye Ran High School. He is also the leader and founder of the RK-5: "No.1".
Tao is a charming man with black, bowl-cut hair covering most of his forehead with a white strip on the right side. He always paints his fingernails black. Although tall and slim like others, his sense of fashion is notably different from the other characters, and is much more relaxed. His haircut becomes more wavy. Also, his eyes used to be turquoise-colored when he first appeared, but it was later turned to grey. It is unsure if it's just a design decision or perhaps an effect of the cease of the use of D. Judging from the fact that Takeo still has blue eyes and since both use a form of D (developed by Frankenstein), Tao might just be wearing contacts.
He confesses to being lonely because no one understands him and his love for technology, except for his nerd friend. Therefore, he found comfort in meeting Woo Ik-Han, who shares his passion. Recently, he forms a strong comradeship with fellow ex-Union members: M-21 and Takeo. The relationship between the three has had a considerable influence on his personality; he is kinder and more social.
Moreover, he is very carefree and relaxed, sociable, talkative and adaptable to surrounding environment very quickly. It can be said, however, that Tao can sometimes become too focused and absorbed in thought, leaving him to carelessly forget his surroundings, such as being approached by a member of Cerberus while aiding Takeo and M-21 at a distance, and perform inappropriate actions leading to others' discomfort or distress, such as eating all of Rai's cookies before realizing what plate he was taking from. He also takes amusement in performing pranks since he taught Takeo "crass" korean language, which causes embarrassment and regret for Takeo.
Tao seems to have a running gag of changing things in the school facilities and the house without informing (or asking) Frankenstein leaving him at a loss such as when he upgraded the security of the school or when closing the school and giving the teachers paid vacation at the same time by impersonating Frankenstein.
Tao (Kor. 타오) is a 24 year old guy who possesses a genius-level intelligence in the technological fields, especially in programming and hacking. He was one of the less cold-hearted members of the DA-5. He is currently residing with Takeo and M-21 in Frankenstein's residence and is also working as a security guard at Ye Ran High School. He is 'Number One' of the RK-5 which is a group of five he formed.
Tao debuts in one of the DA-5 mission's frontal combat missions in a mountain range. He acts behind, tracing the opponents movements and guiding their attack. Upon the completion of the mission, the DA-5 are sent in South Korea on their next mission - finding information regarding Crombel's work in the South Korean base of the Union.
Arriving at the city, the DA-5 station themselves in the ex-Union base and Tao collects information regarding the recent incidents. He finds out that the Union base and agents have been destroyed and there is only one living experiment of Crombel who can provide the information ~ M-21.
While the other members are away, Tao has been busy hacking the local security system. Coincidentally, Ikhan who has been checking the system for his uncle who works in the security department happened to by working simultaneously. Tao is blocked by Ikhan and is counter-attacked by a virus sent by him. Tao replies with another superfast hack attempt. They start to virtually encounter each other and find it interesting. But the encounters are suddenly cut-off (due to Shinwoo's intervention of pulling the plug out).
Tao later hacks the local CCTV footage and locates M-21. He gives the information to his teammates who set out to look for M-21. Once again, Tao attempts to contact Ikhan who has confirmed some data hacked and stolen very skillfully from the security system. Soon he gets a message from Tao. Both start their virtual encounters again while his teammates find and capture M-21.
Tao develops profound interest about the boy who has managed to keep up with his skills. So, he meets with Ikhan at a local cafe after showing up at his front door, having found out his identity and address. Ikhan wonders how Tao found him although he couldn't get any information about Tao. Tao praises his skills and expresses his delight at meeting someone like him which has finally relieved him from the loneliness of being a genius and being pushed aside by brutes. Ikhan sympathizes with him and calls Tao 'hyung'. Suddenly Tao notices something and parts ways with Ikhan. He meets Shark, who has observed his interaction with the kid.
Tao doesn't attempt to meet with Ikhan after the incident. Most of the time the other DA-5 members are away and only once he gets to converse with Takeo regarding having siblings, knowing that his sister is being held hostage by the Union. Elsewhere, Shark finds out that the kid who met with Tao and the children who met with Takeo are friends and Regis is acquainted with them as well. Shark and Hammer capture Regis and the children and bring them to their base. Tao, Takeo, and M-21 are shocked when they see the kids captured. To their shock, Krantz authorizes Shark to kill them all. M-21 steps in to save the children and holds off Shark from killing the children until Regis recovers to take over.
Tao's sensors pick up an intruder alert and Tao estimates that they've about 15-20 minutes before the intruder comes. However, Rai enters sooner than Tao's forecast and uses mind control compelling Krantz, Shark and Tao to immobility. Krantz uses D to break out of it and after absorbing Shark, Krantz turns to Tao to absorb him for enhancement. Tao sees it as the fate of a modified human and gets ready to carry out Krantz's biding but Ikhan stops him; he doesn't want Tao to die. Ikhan requests Rai to save Tao who, unlike others, has tried to protect them. Krantz seizes Tao but Tao slides and getting free, he binds Krantz with cords and shocks him with electricity. However, Krantz attacks Tao and one blow from him puts Tao in a bad state. Rai then steps in to annihilate Krantz. After the battle is over, Frankenstein and Seira arrive and get the children and M-21 moved back home. Tao is told to bring his comrade, Takeo, who's lying on a rooftop of a nearby building.
Everyone gathers at Frankenstein's Residence where Tao does his best to explain the children about the last incident until Rai and Frankenstein arrive. With everything explained to the children, it is decided to erase their memories for their own good.
The later days reveal the more talkative nature of Tao to M-21 and Takeo who have healed from their fatal injuries. Takeo thanks his rescuers and suggests to withdraw but Tao disagrees. He assures that he can perfectly clear their trace so that the Union will know that they had died and also promises to look for Takeo's sister. Furthermore, Tao tells M-21 that he has found out that Dr. Crombel has recently destroyed all data regarding the M-series. Takeo convinces Tao that they should go in order to avoid causing more trouble to people they're already indebted to. However, M-21 stops them from going and Tao joins the household along with Takeo.
Dr. Aris Arc
Tao and Takeo visit Frankenstein's underground lab and Frankenstein hands two modified 'D' pills each to Tao and Takeo.
One evening, when Frankenstein does not return from his usual grocery shopping even after 4 hours have passed, Tao finds a bad news: Dr. Aris and Yuri have come to investigate the annihilation of the DA-5. Furthermore, Tao finds out that the CCTVs on the route from the house to the mart are tampered with, which suggests that Frankenstein might have been kidnapped. So, a search party is formed to look for Frankenstein. Tao hands them communicating devices and stay behind with Regis and Seira while Rai, M-21 and Takeo head out.
Tao gathers information that there were visitors in the abandoned research base and their safe house. He provides the search party with the possible locations to look for clues. Suddenly an explosion occurs from the ongoing battle between Frankenstein and Dr. Aris' biobots. Tao locates it and directs the team to the spot. There they find out about the fabricated existence of Takeo's sister who is actually a role played by Aris herself. After Dr. Aris' consumption of modified D renders her unconscious, Yuri appears on her side, revealing his suspicion regarding Tao and Takeo's survival and flees with the doctor's body.
After everything is cleared up, Tao and Takeo join Ye-Ran as M-21's colleagues and form the Ye Ran Special Security.
Tao works as part of the Ye Ran Security and has taken over the responsibility of renovating the entire security system. One day, a new visitor appears at the school grounds. He sees the trio on duty and is surprised at the presence of modified humans in the school that Seira and Regis attend. He is later revealed to be Gejutel, grandfather and clan leader to Regis. Although he misjudges the trio to be power hungry humans who forsook their humanity, Regis attests for their true characters. Gejutel stays with the household for a while, conversing with Rai and Frankenstein who he has met after a long time and then departs.
Afterwards, another visitor suddenly arrives at the school and makes his hostile presence known by releasing his aura. The security trio goes to check out the situation and find the troublemaker is another noble, Rael. The trio is object to insults continuously hurled by Rael who finds the presence of ‘man-made toys’ absolutely detestable. A fight breaks out but it is cut short due to Seira’s intervention. Tao reports the incidence to Frankenstein. After a showdown between Rael and Frankenstein (who is sent by Rai to ‘courteously greet’ the noble), it is revealed that Rael has originally come to take Seira back to Lukedonia as per their Lord’s orders. Seira leaves with Rael accordingly.
Tao gathers all information regarding the scheduled take-off of Rai, Frankenstein and Regis (after Rai has decided to visit Lukedonia) and prepares to join the trip. He, along with M-21 and Takeo secretly board the plane and they fly to Lukedonia. However, Rai, Frankenstein and Regis disembark just after reaching the Lukedonian skies, unknown to the trio and the plane crashes with the trio in it. The crash lands them in the Mergas’ territory.
When the trio gains conscious, they find themselves in a treatment facility of nobles. Two Central order guards arrive but the trio is able to withstand their mind control and manage to get out of there. They arrive at the Forbidden Region just in time to help out Regis in keeping the guards away from the mansion. After they reveal themselves to Rai and Frankenstein, the latter is astonished to see them there as it is the least hospitable place for modified humans but Rai allows them to stay at his mansion.
After witnessing Frankenstein's battle with Rajak, the trio follow as Frankenstein rushes towards the castle sensing Rai's release of power. They arrive after the clash of the noble hierarchy has come to a cease and Frankenstein has explained the doings of the previous Lord to everyone. Their arrival draws the attention of the nobles and they're introduced as the ones Rai has taken under his wings. Later they leave the castle as Rai and Frankenstein departs for the mansion.
The trio stay at Rai's mansion for a while. A sudden invasion from 8th fleet survivors surprise them. Tao hits them unconscious (to save them from the coming wrath incurred when they open fired at the ceiling) and later they are handed over to the Central Order. Tao accidentally drops packets of ramen that he has brought along from his bag. Rai's attention is instantly fixated on the ramen noodles pack and Frankenstein sets to prepare a gourmet meal (a dinner follows where the Lord attends as well).
Afterwards, everyone returns back to their home, the human world and resume their normal life.
Two newcomers pay a sudden visit to Ye Ran School and one of them engage in a discord with M-21. Tao and Takeo restrain their friend and Tao reports it to Frankenstein. Later, those two people join the school as teachers under the aegis of the government. Investigating them, Tao finds out their true identities as - Na Yonsu and An Sangeen, agents of KSA and also modified humans. Frankenstein tells Tao to keep them under intense observation.
Within the next few days, the trio catch the agents at using thugs on the children (testing out recruit candidates). Tao's report provides Frankenstein the opportunity to have the agents dismissed for the sake of student safety.
Tao arrives at Ye Ran grounds at night to put an end to the duels between M-21 - Yonsu and Takeo - Sangeen. He reveals the extent of his knowledge on the agents - that they are modified humans and their experiments were kept secret from the Union; thus managing to persuade them to a negotiation. A deal is formed between the two parties: RK and KSA agents that they will co-operate with each other regarding the Union and keep their secrecy regarding each other.
DA-5 vs Cerberus
Tao learns of the arrival of Cerberus in the vicinity. When Sangeen gets found out by the Cerberus members, Tao decides that they need to help out. So, he distributes masks to his teammates and sets out to rescue Sangeen from Cerberus.
Tao co-ordinates the battle from a distance as M-21 takes on Ked in frontal combat and Takeo positions himself to snipe. However, Lutai finds out Tao and he has to cut out communication with his teammates to concentrate on his own battle. He is later joined by Takeo and the two of them manage to bring down Lutai. Then they depart to help out M-21 and Regis but is caught and overcome by Taze.
The 12th Elder Arc
Tao is mostly unconscious throughout this arc and wakes up to find the 12th Elder physically transformed having assumed a bat-like appearance. Rai annihilates the Elder and they all return home.
The fugitive of Union who appears to be M-24, is rescued by Rai, Regis and Seira and brought to the residence according to M-21's request. Frankenstein finds it strange that he could be alive after the damage he had received. Tao who has placed CCTV cameras all over the house for security, notices M-24 behaving suspiciously, e.g. running through lab's computers. He reports it to Frankenstein who in turn tells him to keep watch. Afterwards, when despite repetitive warning, M-24 keeps checking the lab's computers, Tao decides to relate the suspicious activities to M-21. But the latter is unable to believe his long-lost friend might be up to something wrong.
Tao gets information from the KSA about the arrival of two more elders. He informs the household about it and decides he would plant false evidences against Crombel to direct suspicions at him so that Rai doesn't get involved in clash with Union again. He takes Takeo and leaves to get the job done. But they are caught by Yuri and Bonerre when they arrive in the old base to plant false evidences.
Tao and Takeo
As they are chained and beaten up by Yuri (who is enraged for their rejection of his fancy for Seira), Rai and team finish off the two elders. Frankenstein and Seira arrive to rescue them with Bonerre being forced to lead the way. Yuri escaped in time as the rescuers have arrived. However, Bonerre enacts self-destruction to injure Tao and Takeo mortally. The wounded duo is brought home where the destroyed lab leaves no chance of their treatment. Rai steps in to revive them despite his own gravely deteriorating health. Both Tao and Takeo are awakened by Rai who collapses afterwards.
Traitorous Clan Leader Arc
The trio convince Frankenstein to train them while Rai has entered a temporary hibernation. The RK team take-off with Tao piloting the helicopter to Frankenstein's Island. During training, despite attempting different group attack formations, they fail to land a single attack on their trainer, Frankenstein. After a while, they get irritated at the repeated outcome. Just then Tao receives an alarming news from the KSA about the arrival of more Union elders. They quickly depart for the city. Frankenstein leaves them once they reach the city skies as they are told to head home.
Tao, Takeo, M-21 and Regis reach home and M-21's cell phone rings. Tao is surprised since the phone is supposed to be anti-tracking and only the RK can call each other. After it's put on speaker mode, everyone hears M-24 aka Mark speaking. M-21 is told to bring the rest of the data to the school alone otherwise the children will die. Tao quickly checks the children's cell phones but doesn't get any response nor is able to track them.
Tao decides to prepare fake data and sends his teammates to rescue the children. When M-21 meets with the assassins and a sudden glare provides them the chance to escape with the children, Tao directs that two of them need to hide the children while one remains to stall their pursuers. Mark, Kalvin and Yuri arrive to find M-21 blocking their way and before they could react, M-21 transforms his hand to create a blow that damages portion of Ye Ran building. Seeing the damage, Tao asks for forgiveness from Frankenstein, dreading the inevitable they'll be facing once he gets to know!
Tao watches as his teammates fight for the children and fall prey to Kalvin's trick, taking poison. Suddenly Rael appears. Tao speaks to Rael through Regis' communication device and manipulates him against Yuri (creating exaggerated stories to fuel Rael's protectiveness over Seira). Tao's machination works as Rael manages to procure the antidote for children as well as kill Kalvin while the other two desperately flees. Tao then further convinces Rael to help them out by carrying the children back home as fast as possible.
The Earnest Wish
The RK and Rael are back at Frankenstein's house with the children. Tao faces Rael who is infuriated at him for daring to make him carry the children but Tao explains to him that he's the fastest and they're running out of time. Tao uses Rael's weakness by adding that Seira will feel sad if the children were harmed. Then he gives primary treatment to the children to sustain them until the other nobles arrive.
The household settles as Rai and the others arrive, albeit none in good health condition. The trio are explained everything that had happened. Frankenstein thanks Tao for treating the children as Rai worriedly watches over them. After that Tao accounts their part of the battle to them and reveals that M-24 is actually an imposter from the Assassination squad after confirming on the battle style M-21 has witnessed. Later, the trio work hard to restore the school as fast as possible and return to the normal lives they have been fighting to protect.
The sudden invasion of Ignes and kidnapping of Seira prompts Rai, Frankenstein and Rajak to follow the trail of Rael and Regis to rescue Seira from Ignes, the trio are left to look after Ye Ran and the house. Before departing, Frankenstein informs Tao of the arrival of Karias who will join them shortly to look after the household.
At school, the trio are visited by Yuri and Mark who have come to finish the unsettled matches (now that they've confirmed no nobles are around). However, they are saved by Karias who makes his entrance (a little delayed to make the perfect timing) to frighten off the enemy. Tao greets the noble clan leader and later leaves him with M-21 to watch over the school while he and Takeo depart to bring back Rai and others from the island.
The household return and the trio further fortify Ye Ran's security. They are on their way to a meeting with KSA. Karias has joined them but a sudden enemy movement catches his attention and he advises the trio to leave the vicinity. The trio take his suggestion and depart.
However, they are caught midway by Kentas. Tao tries to talk out his identity and prompts a distraction to make for a getaway which amuses Kentas very much. As they make for the 14th Section, Kentas catches up and attacks them. With M-21 overwhelmed at the sight of a real werewolf, Tao and Takeo try their best to fend off the opponent by themselves. With Kentas suddenly enraged at the sight of a transformed M-21, Tao and Takeo find it very hard to restrain him from killing their friend. Tao releases an electric discharge while Takeo lures Kentas. Tao becomes elated assuming his attack has managed to defeat Kentas. However, that doesn't prove to be the case and Kentas emerges unharmed and even more furious. Tao looks after the injured M-21 while Takeo draws Kentas' attention. Tao's realization comes true as none of their attempts prove fruitful against the enraged werewolf. So, he and Takeo tell M-21 to escape while they place their own lives at stake to provide the opportunity. However, Kentas is much too powerful for them to hold off and both are easily defeated. As they are about to be killed, M-21's transformation engages Kentas shortly until the modified werewolf prove to be no match for the original one. They are surprisingly saved by Gejutel who arrives at the battlefield just on time.
Tao is delighted at the arrival of "Regis' Grandpa" and the trio witness the experienced noble save them with dexterity of speech as well as avoiding a clash with the werewolf. Tao is worried about Karias who is supposed to fight the two elders on his own but Gejutel assures Karias has been saved too. Just then, the noble Lord enters, followed by Karias and the trio, albeit shocked, realizes the foundation of Gejutel's assurance. Afterwards the trio return to the house along with the visitors and avail quick treatment.
A sudden presence shakes their nerves as the trio, along with the other household members realize that the Lord has brought out her soul weapon, Ragnarok. They all rush to the lab where Rai was and find that the latter has been stabbed by the Lord with the legendary sword. Rooted with shock, they witness as Rai's life force is restored and he returns to a healthier state. Afterwards, the normal life returns to the entire household and the trio return to their duties as special security of Ye Ran High School.
While going through the clockwork check at school grounds with Takeo and M-21, Tao receives a sudden call from Rael. He receives it with a tone of surprise and elation, teasing the Kertia noble. However, the alarming news of Frankenstein's kitchen being destroyed strikes as a bolt from the blue. Recalling how Rai had mentioned that even he is careful with handling Frankenstein's things, Tao 'prepares' (imbibes D) to prevent the most perilous state (Frankenstein going berserk over his 'mishandled belongings') and takes his teammates to fix the wreckage immediately. Tao manages to restore the kitchen with the aid of his group and also makes sure that Frankenstein does not find about what happened.
At a later time, Tao calls Karias and Rael to a meeting where he invites both of them to join the RK team in order to combine forces against the recent strong opponents like Elders and Werewolves. Karias takes up the offer enthusiastically while Rael refuses at first. But Tao manipulates Rael, mentioning that it's Raizel's team he is offending and also mentions Seira as a part of the team to lure in Rael.
After a full recovery from past wounds (received during battle with Kentas), Tao and Takeo implore Frankenstein to experiment on them further to enhance their strength. Tao comments how the enemies are stronger than before and the only one who can get them enhanced in the shortest amount of time is Frankenstein. Despite Frankenstein's reluctance to trial with them anymore than their bodies can handle, they keep on insisting to undergo anything rather than losing people they care for. At last, their appeal is granted and Frankenstein offers to share a portion of the power of his Dark Spear with them. After going through a lot of pain, their bodies adapt to the new power. However, Frankenstein sets a limit to the power usage beyond which the dark power will consume them.
Around the time when Grui and Gaitan begin their action, Tao and the other trainees are on their way in a helicopter. Tao alerts Rael about enemy in the vicinity but fails to convey the location because of communication failure. They get to the area as fast as they could but find both Rael and Regis defeated against the modified werewolves. The trio take over the fight against Gaitan. Tao as well as Takeo use their new dark power. However, not even the enhanced power nor the combined attack is enough to bring down Gaitan. Tao and Takeo gamble pushing their limit but that results in turning on the viciousness of the power of the Dark Spear power which takes over their bodies. The timely arrival of Rai saves them from being consumed.
Tao excels in hacking, though frail in appearance, and while still much stronger than average humans, has not been shown to demonstrate the level of physical prowess that was displayed by his fellow DA-5 members. This physical disadvantage, however, is more than compensated for by his immense tactical intelligence, shown in his tendency to predict and counter enemy movements. He uses a whip in combat which allows a flow of electrical current to shock the bound enemy.
Tao was originally designed for using his technological knowledge to seize control of surrounding systems and discover the movements of the enemy (e.g. by the use of sonar receptors), therefore supporting his team and raising the overall percentage of success. His repertoire possesses a wide variety of skills ranging from gathering intelligence (through the use of hacking), to counterintelligence (e.g. creating secure comm. channels and erasing traces of his presence). These skills easily place him as the head of tactical support during his involvement with the DA-5 and, in later chapters, the leader of RK-5.
Tao, besides utilizing his intellect, can also physically attack others using an electrified wire, where he has been seen whipping and wrapping enemies with it, and then electrifying them. When he needs, Tao can collect the electricity from the surrounding areas.
Using the same wires, he is able to defend himself. He wraps the wires around his own body to resist attacks directed on him. During his fight with Lutai, Tao showed a new type of attack in which he made a spear using the wires and pierced Lutai with it and further increasing the damage by electrifying him.
Like his fellow mates from the DA-5, Tao can use D (three levels of a stimulant drug: a lesser effect [30%], a destabilizing one [100%], or a last resort [200%]) to temporarily boost his physical strength.
After the implantation of a portion of Dark Spear, his physical and spiritual abilities are increased dramatically. To trigger its effects, he partially covers his body with the aura of Dark Spear and part of his skin turns to dark purple. By using much more power, he can increase the effects of Dark Spear. He gains long whip-like weapon from dark aura and his left hand covers with it after activating second stage of this power. However, like Frankenstein he loses his control slowly.
Dark Empowerment: Tao can imbue his regular wire with the energy of darkness from Dark Spear. He is able to hurt a strong werewolf by this technique.