As that look of... annoyance? Impatience? Plays out on the ninja's face, something about the supposedly rigid and unmoving grin that arcs across what Sans calls a face manages to give the illusion it's widened in amusement. Fussy guys like this are always a hoot to wind up. Not... too much; Sans gets the distinct impression that this guy might just be dangerous. Then again, he's got something of a knee-jerk bias about humans.

Blame generations of his kind being exiled under a mountain by humans scared by what they didn't understand.

He is the very picture of patient indolence, cradling his head in the cup of one hand, in a full-body lean against that railing, too short to be in danger of toppling over the edge. Daring to look comfortable even, in the face of Sasuke's mounting aggravation. He might like messing with this guy, after all.

"I thought it was pretty clear we ain't from the same species. I mean, that's what you meant before, right?" drones the skeleton, grinning, "Hhhhhh...." he sighs, lunglessly, "Eh, I'll just skip the explanation and make it real simple."

The skeleton makes a sound as if he's clearing the throat he obviously doesn't have. Puts up his other hand.

And, as he wiggles his phalanges, intones with entirely too much gravitas: "Maaaagiiiiic."

Dropping his hand, the skeleton's shoulders hitch in a brief chuckle. "I'm a monster, pal, it doesn't have to make sense to ya."