The Eastern Kingdom:
Emperor HanGeng - Known for his gentleness and kind-heart. He forgives nearly everything and anything. Under him, the kingdom is in an enchanted spell of awe and admiration for his beautiful heart...and dangerously lethal fighting techniques. He loves his wife with all his heart and is completely devoted to him. He's also extremely devoted to his children. HanGeng wonders why the two countries fight for the Floating World; however, he has never truly made a move to end it since it's all the two kingdoms have known for centuries. He knows it's wrong, but he just can't bring himself to stop it. (Aligned with Water)
Empress Heechul - Beauty beyond compare, this empress is one to be reckoned with. He has sharp tongue and a fierce personality to match; however, although his outside is rough - he is just merely a diamond in the raw. Don't let his cold appearances full you either. His heart is as warm and beautiful as his exterior is, because he truly loves the Eastern Kingdom and his children. He doesn't say or question about the war since he is the kind to dislike change - in anything. Heechul is also a jindallae. Heechul can also see into the future since he has the ability of fore-sight. (Aligned with Fire)
Prince Siwon - The eldest son. He is twenty years old, and is the next in line to rule the throne once the year ends. He has both his father and mother's amazing looks, along with his father's skill in battle tactics. However, through that, he has a soft heart that wishes and hopes no one will have to die any longer. He is also very close to his younger brothers. At the moment, he is supposed to be fighting in the war; however, Heechul doesn't want him to. (Aligned with Fire)
Princess Donghae* - The second oldest. He is eighteen years old and also a jindallae - which is a slightly uncommon occurrence. Being a jindallae means he can bear children, even though he is not a woman. The most current generations have many jindollaes, though. Donghae is beautiful like his mother. Most of his personality is like his mother's as well. Out of all his brothers, he wishes and prays for peace the most because he doesn't want to see his brothers go to war. Donghae can also use dance magic, and is an extremely strong magic user - having inheriting the magical abilities of an Ancient - known as Aquelle the water faerie. (Aligned with Water)
Prince Kibum - He technically isn't the son of HanGeng and/or Heechul. He's the son of a brave war hero who saved HanGeng in the midst of war. Of course, his father died; therefore leaving Kibum parentless since his mother died much earlier on due to sickness. His father told HanGeng to take Kibum in and raise him. This all happened when Kibum was just three years old. He is now seventeen. He's also very mature for his age, and very quiet. Although he lost his father to the war, he is neutral on the war because he thinks that if the war ends, the kingdoms will be left without a purpose. Therefore, he doesn't care. (Aligned with Water)
Prince Kyuhyun^ - The youngest of all the princes and the most likely to become a scholar because of how intelligent he is. He has his father's handsome features, but his mother's wit and tongue. He's a sharp one, with what seems like a heart of ice. He prefers to keep to himself; therefore, he doesn't tell others much or say anything unless it's some witty comment or if he has a speculation on something. The one thing that will rile him up; however, is the war. Since he is close to Kibum - who's the same age as him - he hates the war since it took so many of the people's lives. Kyuhyun is also a magic user like his brother Donghae; however, he uses singing and rhymes for his incantations instead of physical movements. (Aligned with Fire)
The Western Kingdom:
King Kangin - The king of the Western Kingdom, he is very strong - inside and out. He has a noble heart that is merciless when need be - with a soft side that has his wife, Leeteuk, all over him. He looks menacing; however, to his people, he is kind-hearted and makes the kingdom prosperous. He doesn't understand why he needs to fight in the war, but it's all he ever knows - even since when he was just a child because his father used to take him to the war grounds to show him what he'll have to do in the future. (Aligned with Earth)
Queen Leeteuk - The queen of the Western Kingdom, he has a soft and gentle heart. His features are soft and pretty, giving off a warm feeling that his counterpart in the Eastern Kingdom lacks. He loves the people, Kangin, and their children completely and utterly. And being such an umma, he also goes around and does things such as cooking or cleaning with the servants. He - unlike his husband - wonders about the war very much. He prefers to have peace, and once, wanted to go to the Eastern Kingdom to discuss a peace treaty with them. However, Kangin stopped him since there was too much at risk. Leeteuk also doesn't have the greatest of health, falling sick constantly. Although he has never fallen completely ill to the point of where he's on the verge of dying since he's a fighter - just like Kangin. Leeteuk is also an azalea - the Western Kingdom equivalent to a jindallae. (Aligned with Air).
Prince Eunhyuk* - The jewel of the Western Kingdom, and the eldest prince is Prince Eunhyuk. He's the oldest - being about nineteen. There's only a few weeks left before he becomes the king. Like his father, his exterior and calm and composed - slightly menacing at times even. However, his heart is that of his mother's - only with his father's merciless when needed be side. Skilled in sword-fighting, archery, and strategics, his father trained him well to become the next king who will fight for the Floating World...and Eunhyuk honestly doesn't care. He thinks the fighting is stupid; however, he is pretty neutral on the fighting. (Aligned with Air)
Princess Sungmin^ - Prince Hyukjae's fraternal twin. He is the same age as Eunhyuk, obviously. However, their personality's are completely different. Although Sungmin has the beauty and warm looks of his mother, his personality seems to manifest from nowhere. He's cold and guarded, not one to let others in very easily. However, once you get to know him, he's the most adorable person ever. The only ones who know of his true personality are Leeteuk, Eunhyuk, and him. Sungmin is also an azalea, like his mother. However, too bad he dislikes all those who have tried to get close to him. Such as the past suitors from the other kingdoms far away. The reason for this is because he lost his lover in the war, and since he doesn't want to get hurt again, he tries not to get close to others. Sungmin hates the war because his lover was lost in it; however, he also hates the Eastern Kingdom since his lover was killed by one of them, and he can also use magic. Him being the only one in his family being able to use voice magic. (Aligned with Earth)
Princess Ryeowook - Ryeowook is the gentlest and sweetest of the three royal siblings. He's known for his amazing meals and sweet smiles that can bring even the coldest person down to their knees for him. However, behind those innocent features and soft looks is an intellectual mind that many can fear. However, he only ever uses that intellect to get his lover to do things for him; therefore he isn't really threatening. He's also an azalea, and he hates the war because of how much pain it caused Sungmin. (Aligned with Air)
Other:
Yesung - A doctor, a magician, and a quirky scholar that travels between the kingdoms on either side of the River of Glass. He goes where his assistance is needed, and is the lover of Princess Ryeowook of the Western Kingdom. He knows many things, including what's located on the Floating World. However, he keeps to himself. Like many others, he wants peace for the kingdoms as well. However, he keeps his opinions to himself. (Aligned with Air - originally from the Western Kingdom)
Henry - An assassin that works for the Eastern Kingdom. He's Donghae's personal servant, although he's technically from the Western Kingdom. He's a mysterious one. (Aligned with Earth)
* = Main Characters/Coupling
^ = Second Main Characters/Coupling