The Four Heavenly Sources, the original source of the Four Trees, was born in response to the destiny. It should have peacefully served as the core of the Four Realms until the Four Realms dissipated...
However, fate is unpredictable. As time passed, Sijiao Tianyuan actually gained self-awareness, and then quietly left the Sijiao Realm.
The Buddha said: There are seven sufferings in life: birth, old age, illness, death, meeting of resentments and hatreds, separation from love, and failure to seek what you want.
"When we begin, we know that there will always be an end." - Huang Quan (Ye Lin)
"I love you without any purpose, I just love you." - Luo Hu
"Everything has a price, and the price of happiness is pain." - Death