Gu-En had the appearance of a tall, muscular man. He had short, white and disheveled hair and blue eyes. He wore a suit of armor and skin with his right arm bandaged.
He was described as a man reckless as a wild boar as Zeno stated and that he and Kija, the present Hakuryuu have some similarities between them.
A series of conflicts were still happening after the death of the King, such as the capture of Abi by people who wanted the powers of the dragons, but fortunately Shu-Ten and Gu-En managed to rescue Abi. Gu-En and the other dragon warriors (except Zeno) left the Hiryuu Castle to continue their lives in another direction. Before leaving, Gu-En said that he will wait for Zeno to visit him no matter how long. He kept waiting for Zeno even on his death bed but Zeno never visited him.
Dragon's Claw: The Original Hakuryuu holds the power of the dragon within his right hand, which becomes the white dragon's claw when he uses it. He has been seen using it on the battlefield to kill solidiers, easily piercing through their bodies.
- Immense Strength: The claw of the white dragon is said to have ten times the strength of a normal hand and the ability to tear anything to shreds.
- Akatsuki no Yona Fanbook