Both are queer webseries, specifically in the BL/GL genre. Meaning they're lighthearted, have shallow stories, and each has a slightly more serious element to it. I recommend them if you don't want to think too hard. They're similar in that both of them feel like they are based on webcomics. While Legend of Yun Qian is magical, Nobleman Ryu is not, though both take place in the past as a costume drama. Are either of these the best thing out there? Not really. But that doesn't matter to everyone. If you know you are easily pleased by BL/GL web series with a light hearted feel, then go for it.