I'm pretty sure no one could make a man bigger than Jayne look like a girl, especially with that face. Saying "He's a master of disguise" don't change nothing. You can do subtle things to suggest different things, but I doubt you can make a big man smaller and back again freely.

I could say my character is a master of manipulation, and just change his personality whenever I feel like, to do whatever I want, and say, "Don't think about it, he's a master of manipulation" or somesuch. I don't know about Afina, but I sure as heck wouldn't allow superJayne manly man to become pretty womanly woman.

And, it's [i]He's[/i], not [i]His[/i].

And the only really notable thing about that "true appearance" is how insanely buff he is. Otherwise, the only difference from any other male anime character is that his hair is an unusually dull shade of green. And that's about it.