Why does the water mirror say that Yan Yu can only be seen in this life?

Yan Huan said that he would only see Yan Yu in his life. Wu Haotian was indifferent to them, but he could see Yan Yu every life. At first, I didn't understand. Later, I felt that the relationship between Yan Huan and Yan Yu was different from that between Wu Hao and Lu Xiaolu, because Wu Haotian (Sun Ce) was indifferent (Zhou Yu), and Lu Xiaolu (Da Qiao) and Yan Yu (Xiao Qiao) were related before their reincarnation (the real Three Kingdoms period). Yan Huan (water mirror) has nothing to do with Yan Yu (Xiao Qiao) in the real Three Kingdoms period. Only in this life have they just become brothers and sisters, so Yan Huan (Yan Huan, who has nothing to do with the identity of the water mirror) met Yan Yu (who has nothing to do with Xiao Qiao's identity), but Yan Huan originally cared about his brotherhood as Yan Huan and Yan Yu in this life, so even if they are reincarnated, they are not necessarily brothers and sisters. Yan Yu also became two strangers, that is, the relationship between water mirror and Xiao Qiao. Even if they found their memories after their strength was enhanced, it was only before the reincarnation, that is, more than a thousand years ago. The real Three Kingdoms period was the memory of Shui Jing and Xiao Qiao, and there was no memory of him and her as Yan Huan and Yan Yu in the last reincarnation.