Ok many people are not liking dream sequence because they find Tan tia jin and Le xi wu characters more interesting and their dynamic is interesting and they love shaddy Tan Tia Jin in black clothes. Even i also thought i will skip dream sequence but when i skipped ep 13 and went to watch ep14 i didn't understand anything.
Why this arc is so...much more than story of Ming Yue and Sang ju i will write it below.
NOTE- I haven't read the entire novel but all these things are told to me by my other friends in MDL who have read the novel.
this arc was important
1.we get to see how all God's died, how God of time was trapped in abyss and waited for 10000 years for li su su to come so that he can tell her the way to finish evil bone , so that no other evil God can come alive.
2. We got to know Li su su may have both demon and immortal genes(origin/roots). I heard she was adopted in her sect by her adopted father(whom we saw in ep 1). And she is child of the God turned demon who was in love with Godess of space and they both had Li su su. I heard he will back when li su su will go back in real time. We saw in ep 15-16 he didn't die but he was trapped.
3. We got to know all God's died(there were 12 Gods in total) (and the two God's -1. God of time was trapped in abyss and 2. God of war (mingyue) is drowned in misery of loosing Sang ju and has given up his human form and he is sitting inside river MOHE so that he can stabilize mohe river aS all the people of clan was killed by evil bytch Tan Hiun(ye bing chang) and Sang ju perished, so he is stabilizing river otherwise it will bring flood. This is the reason when Tan tia jin becomes evil God their is no God's left to fight with him, only immortals left , which is why li su su has to go back in time so that he can destroy evil bone before he becomes evil God
4. Devil God from 10k years ago has same face as Tan tia jin because Devil God did some favour to yuye tribe (Tantia jin's mothers tribe) and asked her child as a sacrifice so that the child will also have evil bone and he can become next devil God,
in this way he can come back to conquer three realms and 4 continents. So Tantia jin
has evil bones therefore he looks like old devil God
5. This dream will teach Tan tia jin to not let go the person he likes and to keep her close. Where as Li su su will learn not to love too much and to focus on her goal
6. This dream will let li su su to get closer to develop 9 nails which she will pierce in TTJ's heart to seal evil bone. As dream was one of the element needed to destroy evil bone which God of time mentioned in Abyss
10. And they will start developing feelings towards each other after dream sequence.
So this dream sequence is not a waste , i really hated dream sequence from eternal love pillow book but this is good