That proposition comes as a shock. So much so that Elsa isn't certain of how to react at first, simply blinks at Sans in surprise.

"You-- You'd do that?" She doesn't know what to say. It's such a kind offer, and one that she appreciates greatly. In fact, she'd very much like to take him up on it, but... "Do you think that you really could? Our powers are... They seem very different."