Prince of the Red-light District

Prince of the Red-light District (홍등가의 왕자, Hongdeunga-eui Wangja) is a derogatory term used to name some of the Tower inhabitants who have inherited the blood of Zahard.

History
According to Rachel's mysterious informer, their existence is a shame to the King of the Tower who regards them as his "worst disgrace" and has tried ever since to hide them. Likewise, Hwa Ryun spoke of one of them as "the most terrible affair left by the Ten Great Families and Zahard".

Ring
They bear a red ring engraved with the symbol of Zahard. The rings were crafted from half of the Key of the Tower. Thus, it is said that only when all Princes gather on the 135th Floor, then this floor may be conquered.

Powers and Abilities
They are said to carry a power which they were not meant to hold.

As both of the known ring bearers have proved they could ignore death to some extent, some readers speculate they are covered by Zahard's immortality contract to some degree.

Known

 * The "Yellow Prince", Ja Wangnan

Plausible

 * Karaka

Notes and Trivia

 * Officially, Zahard does not acknowledge any Prince.
 * The story of the Princes shall be gradually revealed.
 * SIU suggested that the Zahard's symbol bearing ring might be made of clotted blood.
 * Jaina Repellista Zahard stated that the time had come for "them" to appear. She might have been referring to the ring bearers. She also claimed that soon the Prince of Zahard would return, the relationship between the two princely titles remains undisclosed.

On the Translation
A Red-light district is a prostitution and sex-oriented business urban area, so is a 홍등가 in Korean.