An Sangeen (Kor. 안상인) is a modified human and an agent of the KSA. He is married to Na Yonsu, a fellow KSA agent and his current work partner.
Sangeen has grey hair, a black goatee, and has ear-piercings. He maintains a collected expression on his face. He also has the habit of smoking. His attire is similar to that of a typical agent as it is a simple black suit.
He is a cool, calm, and collected person who acts when the situation calls for it. He is Na Yonsu's partner and covers for her lack of foresight due to her headstrong temperament. Even though he doesn't show much emotion, he still wants to protect his country from modified humans.
He also tries to put up an act when needed and argued with Cerberus in order to get hurt so that he could later get away from them to meet Tao, M-21 and Takeo. After forming a sort of alliance with them, he gets caught by Ked and Lutai and as he makes a run for it, he breaks up the contract as he has no intention of involving others in his problems.
At some point in the past, An Sangeen took part in an experiment and became a modified human along with Na Yonsu, in service of their country. This experiment was done in absolute secrecy within the KSA and all the details of it were strictly kept away from the Union. He is married to Na Yonsu and works as an agent for the KSA along with her.
An Sangeen and Na Yonsu appear while investigating the big crater created in the battle between Frankenstein and Rael that appears in the city. Later, they are sent to Ye Ran in order to gather information on the possible KSA recruits: Shinwoo and Ik-Han. During that time, their cover is blown and they place the children in danger in order to test Shinwoo's skills as the special security team kept an eye on them.
Later, Sangeen accompanies Yonsu on a night charge into Ye Ran to check her suspicions on one of the special security members: M-21. He stands guard on the top of the building while Yonsu searches the grounds. There he is confronted by Takeo and they engage in a short duel, however, they halt when M-21 and Yonsu stop battling and Tao arrives.
There the agents discover the identities of trio and theirs are revealed as well. Both teams come to a pact of keeping their secrets and work in an alliance against the Union.
After Cerberus arrives, Sangeen and Yonsu serve as their local guides. Sangeen decides to discuss with the trio regarding Cerberus and feigns an act to get hurt by them in order to later escape and meet the trio. However, upon his return, Ked and Lutai discover his identity as a modified human. He is chased by them and falls prey to their attacks but the RK arrives to his rescue. M-21 flees, taking him away from Ked, and later holds him off to let Sangeen escape. Realizing he would only be a burden, Sangeen does as told and finds Yonsu on his way. They decide to join and help the trio, hence returning to the battle field.
Sangeen and Yonsu maintain co-operation with the trio, informing them of all the news they get from the Union. On one evening, they notice a chaos in the city alleys and inform the trio. But before either group arrive at the spot, Raizel, Regis and Seira find a fleeing experiment desperately fighting his pursuers. When the KSA agents arrive, Regis has already taken care of the pursuers so the agents take the experiment to their treatment faculty as Raizel seems to know him. Later the trio arrive there to find that the modified human is M-24.
In the following arcs, the agents are rarely shown although their reports are frequently mentioned.
An Sangeen is present when Lunark visits the KSA Headquarters looking for Frankenstein.
Woo Ik-Han: One of the candidates for the KSA program. Due to not being the teacher for the computer class, he doesn't know whether he's suitable.
Lunark: She's one of the Elders who came to deal with the events in Korea. She later asked them for help in locating Frankenstein. The two don't have much of a relationship.
Powers & Abilities
Being a modified human, An Sangeen possesses physical capabilities well beyond that of a regular human. His overall skills and abilities have been complimented by two Cerberus members. He is fast enough to keep up with Takeo who is known for his speed, fighting equally against him without much trouble (although Takeo wasn't fighting using D or boost-up pills). He has a sense for strategy, attempting to use the environment to his advantage against a stronger opponent.
An Sangeen is able to attack using small blades made up of his aura as seen in his fight with Takeo and later against Cerberus. He can use multiple blades to attack from distance and even wield them in close combat. He shows high accuracy with these blades, being able to use them to stop all of Takeo's bullets that were aimed at him.