What, they're just going to teleport in? Asshole move, but it doesn't really phase him. There's the slightest raise of an eyebrow at the newcomer's appearance, but otherwise he doesn't comment on it. (If the situation was less serious he'd have been tempted to joke that they must have been looking for Jean instead, but this is neither the time nor the place for that.)

"So who the hell are you? And what do you want with me?" Blunt and to the point, without wasting time on niceties. Eren's still tensed like he's itching for a fight, but manages to control himself. ...For now.