"Then how'd you get all the new magic?" Sans asks. He's trying not to be super confrontational, because it doesn't really seem like it would help at this point. However, while he's having a hard time trusting his own perception at the moment, he knows what the others have said and learned from Noa. Their souls are corrupted by the void, even if it's in a kind of roundabout way.

"If you're taking power from something, it's a part of you. You're letting it mingle with your magic, and you gotta know that could mess with your head, right?"

He feels like this isn't going to work. No matter what he says, Papyrus can think of up excuses - hell, he does that all the time normally, about perfectly mundane stuff. What's his next move? He's gotta figure it out before Papyrus makes his move first.