The fact that his tattoos glow has been previously mentioned, yes.

This form of bending, unlike other, is internal; a bending of your inner energy and not of the visible elements. It's the original form of bending ( that we know of at least ) and is essentially different. I don't see how this point is so hard for you to understand.

I'm ready to agree to disagree, i don't see much of a future in this discussion.