This simple profile sketch of Adan, by Toyo Ozaki, conveys a good expression of his character. Calm and collected, with just a hint of a smile, he seems like a genuinely nice guy. Maybe shy and quiet, but nice.
It's an interesting contrast. I'm writing Adan (as in, right now, I was taking a little break to visit Fringes) and I am not at all picturing him like that.