So I was thinking how Ryuu, and really no one on here has a voice actor so I got to thinking about what Ryuu sounds like when I type as him and this is the voice that I hear, especially after the time skip that we just had.
Chris Pine from Rise of the Guardians. (he plays Jack Frost)

Kuro's voice actor is the voice actor for Uryu Ishida from bleach.

And Asa's is the voice actor is Isshin Kurosaki.