Many people are saying that the last scene was Chang Yi's dream, well that is impossible. If he was dreaming he would imagine Yun He as a fox not mermaid. He was surprised that she had turned into a mermaid. So if we use common sense we can see that it's a clear happy ending.
I was re reading the novel and realized that the drama version has made a few plot better than the novel. Like how they got married. In the novel they get married without ShiYi's knowledge. That was unacceptable to me. But in the drama he proposed and they went to get married together. Even though it was simple it was so beautiful.
Since part 2 is more in line with the novel, it's easier for me to catch up even when I am watching it raw. I am so in love with part 2. This is the part I wanted to see so much.
Watch here. They are providing subtitles too.
In the novel they get married without ShiYi's knowledge. That was unacceptable to me. But in the drama he proposed and they went to get married together. Even though it was simple it was so beautiful.