Yuuri Shibuya
Talk about a confusing kid. He claims he's a Mazoku -- king of them, in fact! -- but he's playing the naive, idiot kid really well. Zelgadis really wants to be too smart to buy that again, but he has to admit that Yuuri really seems too dimwitted to be evil. Doesn't mean he's about to like the kid or anything ridiculous; even if he was willing to take the chance, it's the principle of the thing!
Shipping potential: If Yuuri actually managed to, with sheer perseverance, get on Zelgadis' better side, he'd be pretty well on the young side, but Zelgadis might be a bit intrigued by his sweet personality. MIGHT.