I cannot but feel that there is a lot of things that seem off.
First, his beard: is it me or does it inflate weirdly when he talks.
Then, the book: when he put his fingers on it, it doesn't touch it. I find it very flagrant but it might only be me. The book also seems very plastic. Like, I don't think it could be possible for Sejong to even turn the pages. Like, soooooo far from Kristina's book.
The moves of the hands is convincing, though, and the rest is quite pleasant.
However, I cannot but say that, from the beginning even and confirmed right now, that Sejong is, in my senses, nothing as a "clone" to Yongle, even far from it. They're very distinct from one another. Faces completely different.