Bin and Gok doesn't age anymore because they are vampires, but how about Hwa? does he age ...

I think he does age normally because he is a lycan

We don't know yet...he is the first vamp/lycan. He may grow up to like age 25 and then stop aging. I wonder if he dies would he become a full vampire naturally?

It'd be really interesting if they decide to show that part of their life. I really do want to see how t'll play out for the son and lover pair in the future~