Number Seven Under Heaven is the daughter and seventh child of Greatest Ambition Under Heaven, the Patriarch of the Elf Clan. She is embarrassed by the ridiculous name her father gave her so she likes people to call her 'Seventh Sister'. She is the one and only princess of the Elf Clan, the most precious pearl of the entire clan. She fell in love with Xiao Yun, who was then the much maligned Young Patriarch 'Yun Xiao'. The entire clan objected to her relationship with Xiao Yun in the beginning.
When she first appears, she is dressed in a light green, tight-fitting bodysuit. Her face is delicate and pretty while also having a heroic aura which would not lose to men. She has two long pointed ears and a pair of semi-transparent, butterfly-shaped wings on her back.
Like the other members of her Elven family, she has a direct and upright personality. She is very passionate and loyal but also very stubborn. When her entire family was against her relationship with Xiao Yun, she still sneaked out to meet with him and remained with him. She even threatened to leave the Elf Clan to be with Xiao Yun.
She was a subject of a plot to incite conflict between members of the Twelve Guardian Families that supported the Little Demon Empress, Huan Caiyi. When she sneaked out of the city to meet Xiao Yun, they were ambushed and the assassins wanted to kill her and leave Yun Xiao alive so that the Elf Clan and the Yun Family would fight to mutual destruction.
She fell in love with Xiao Yun but the entire Elf Clan opposed the relationship because of his questionable origin and also the weak status of the Yun Family. The entire clan changed their mind after Xiao Yun's status was raised by being bestowed kingship. Demon Empress Huan Caiyi setup the marriage between between Xiao Yun and Number Seven Under Heaven which Greatest Ambition Under Heaven quickly agreed to. Yun Qinghong presented the Elf Clan with an engagement gift of ten Overlord Pellets.