Some viewers don't like the strange endings but I think when you know smth about the culture you understand it.
The plot is highly inspirated by the Daoist mythology and mediaeval Chinese literature (as Biographies of the Deities and Immortals by Ge Hong or smth like that). Actually it is a traditional Chinese story about how deities come to live between humans and humans become deities (though in the 21st century communist China one can call them 'aliens'). In these classic mediaeval novels it is not often explained with details how the human character reaches immortality and passes the magical way of self-cultivation, we just learn that at the end he/she went far into the mountains - as the leads do here.
So, in both endings the leads neither die nor live normal human life. In first variant the leads are magical trees, in the second variant they don't age, live in a mountain temple and one can see them only if they want it. They merely become supernatural creatures of the traditional Chinese myths. As highest beings they can take the form of trees or of humans.
