Shou En has a dragon-like appearance, and has a tail, scales all over his body and sharp teeth. His eyes have a light color. He usually wears Kou's traditional clothing and has a shoulder protector on his left shoulder. It seems he can change his size, but even in his smaller form, he is far taller than a human and the hugest of Kouen's monsters.
Shou attends at the Emperor's funeral and is located with the rest of the court, with the traditional mourning attire.
When a priest reads the testament and Gyokuen Ren is appointed the next Emperor, he, Seishuu Ri, Kin Gaku and Kokuton Shuu rise up, enraged, because Kouen was supposed to be the next Emperor. Shou and the others listen at Gyokuen's explanation of her being the next Emperor instead of Kouen, but they know they have been fooled. Immediately after that, the court splits in two, with Gyokuen and the Imperial Priests in a side, and the army and the Imperial Family in the other.
Alibaba Saluja is fighting against the Black Djinn, and is about to use his Extreme Magic to eliminate them, when Shou interferes and attacks the Black Djinn with a breath of fire, which destroys them. Then, Shou, Kouen and the other three monsters appear, all riding carpets except for Shou, who has increased his size incredibly. Kouen analyzes the situation and, when he sees Kouha Ren's state, says to his Household that if the the enemies are too much for the others, they will deal with them with their strength. The four monsters roar in approval.
Shou joins the other three monsters' fight and breaths fire again against the Black Djinn.
Shou stares Alibaba heading towards Kouen, silent. Aladdin begs Kouen to send back his soldiers, saying that it won't matter if they are from Kou or Reim, they will die. While Seishuu Ri doesn't believe him, Shou, Kin Gaku and Kokuton Shuu are surprised, and don't seem to understand what he means.
- Breathing Fire: It's been shown that Shou can breath fire from his mouth. It is very powerful since it can burn numerous Black Djinn in one shot
- Size Change: Shou seems to be able to change his size as he pleases. When he attended at the Emperor's funeral in Kou he had a more or less normal size, which was taller than a normal human but not more than the palace. In the war of Magnostadt he appears with the height of a mountain. His strength increases proportionally.
- Although he was introduced in Night 116, his name wasn't revealed until Night 182.
- His first name means Clear. His last name means Flame.
- "Shou En" is the Japanese pronunciation; in Chinese his name would be Zhāng Yán.
- At first, Ohtaka thought of making him and Drakon brothers.