Zi guang is a famous and powerful peak 2 Lotus saint realm master from the Sacred race.
His eyes are purple as well as his skin.
He's the owner of the Purple light Prisme, a 2 lotus saint artifact capable of creating devastating purple lighting, it's also this same artifact that gives him his title "Purple light Saint".
In the distant past he fought fiercely with Cang yuan and gives him a lot of trouble when the latter was hiding with baby YaoYao.