Responses
not much spoiler
The golden hair and red eyes are symbolic of the imperial family since the founder of the empire had those characteristics. Kiolle is not Kishiar's and Keilusa's cousin (Kiolle is the adopted son of Keilusa the Emperor), but they are related because since they share those characteristics, they are all descendant of the fist emperor.
I remember someone saying that kiolle might be kishiar's cousin or smthg since him, kishiar and Emperor they all got blonde hair and red eyes and eye and hairs are very much correlated to family background in manhwas .