@Dxxsey I think that's Dowun. That's been hinted since begining, as his name has a chracter for 'cloud' in it (chap 3).
Lyon often has been presented with lotus flowers. In buddhist artwork it usually symbolizes purity , as if floating above the murky waters. I do believe it represents Lyon's heart in corrupted world of politics of the palace.
And this chapter would cement that Lyon is indeed a 'flower'.
But I don't think that means that Dowun is ML. Title is 'The Flower That Was Bloomed by a Cloud', so it's about Lyon and Dowun's relationship for sure. But flowers are not growing propely in a shadow that is under a cloud. Flower withers in the shadow. What it needs is sun, and I think that 'sun' would be Baek Han.
In chapter 62 Lyon, while saying that her sense of morality was preserved thanks to Baek Han, say: "(...)and my yearning for that bright LIGHT of yours has grown deep within me".
So it may be more of a story about finding what's important to heroine.