Yu Han Sung (유한성, Yoo Hahnseong; or "Yu Han-Sung") is an Advanced Ranker and the former Test Director of the Second Floor. Despite his feminine appearance, he is actually male. He is a well know ranker partly because he rejected to be a High Ranker. He is also well-known as a genius Wave Controller as stated by Lo Po Bia Ren, a member of Zahard's RED Assassin Unit. He is a key member of FUG in taking Viole to the top and the main antagonist of Part I. He plays an important role as a character because he is well versed with several details surrounding the main story of Tower of God.
(About Khun Aguero Agnis) "He's such brilliant boy. That pride, courage, talent, cunningness and arrogance. I just want to break him into pieces."
(To Rak Wraithraiser after compressing his form) "Huh? I'm sorry. I couldn't see you because you were too small. Oh my. Sorry. Too small. One moment. Just one more spin..."
(To Lero-Ro) "We say we are testing their talent, to see if they are worthy. But the real purpose is to keep the Tower from chaos. In other words, this is the seawall to prevent the tsunami, that can shake the Tower."
(To Lo Po Bia Ren while fighting him) "They really can be like that. But sometimes they look smaller, once they are exposed."
(To Lo Po Bia Ren) "I'm telling you that I will help you achieve your goals. This is Evankhell's hell where we sort out the dangerous from the Tower. And I am the Deep-Sea fish lying in wait to gobble them up."
(Talking to himself) "Soon a tsunami will shake this Tower. And it will start right here."
(To Evan Edrok) "Shouldn't Zahard pick up the garbage that they dropped along the way?"
(To Rachel) "I've received word from Headon-nim. Miss Michelle Light. It must've been tiring to complete the first test. Ah, perhaps it wasn't too difficult. Since you were with a person Headon-nim prepared..."
(To Rachel) "Miss Michelle, you need not worry about anything. The teammates you'll need, the rights, and strength, I will steal all of it for you."
(Talking to himself while drinking a cup of coffee) "The death penalty? Too bad. I wanted to try a lot more coffees. I guess this is my last cup."
(To Ha Cheonhee) "Let the Regulars go right now!! Only I, the head of the floor of test, am allowed to torment Regulars!!"
(To Baam after watching him beating many of C-rank Regulars) "Well, I guess now you might finally be worth fighting them."
(To Baam) "Jinsung Ha wanted to turn you into more than just a slayer. If you understand what he was after, no matter how strong your enemies are, don't lose your own sense or self. That's the only way to shine in the darkness that is FUG."
Notes and Trivia
Despite his feminine looks, he is actually a male or guy. SIU confirmed this in his Q&A with fans at NAVER fancafe in 2010.
Yu Hang Sung is an important character in the entire story of Tower of God. Even though he did not appear much at the beginning of Season 2, he is close to important main stuff. His role can be seen in the fact that his Data Form was able to convince Khun Eduan's data on the Hidden Floor of Baam's existence and was able to persuade Evankhell to go along with some of his plans.
SIU stated in his Q&A 2010, that Yu Han Sung is very close to being a High Ranker, which means that would make him be in Advanced-Ranker category. This was later emphasized in his encounter with Lo Po Bia Ren. According to Ren, Yu Han Sung rejected High Ranker's position by coming to Evankhell's Floor.
SIU also stated if Yu Han Sung didn't mess around on Evankhell's Floor, his rank would have been similar to Ha Yuri Zahard, which is a top 500 High Ranker. This statement might explained Yu Han Sung's action of rejecting High Ranker position; he was avoiding to be promoted as High Ranker by playing and messing around.
Rak referred to Yu Han Sung first as "Golden Turtle" and later as "Coffee Addict Turtle".
He is the endorser of the Maxim coffee brand as seen in a vending machine.
It is yet unknown how Han Sung obtained knowledge on V whilst still a D-rank Regular.
According to SIU, he just loves every instant foods.
As suggested by SIU, Yu Han Sung's name has a meaning. Yu-Han in Korean means finite. Sung is a suffix that means having characteristics of. This hints that Yu Han Sung life is finite, which would make sense given his connection to Hendo Lok Bloodmadder.