[She punches her hand with her own fist, her eyes practically glinting with Fight Energy™. Better get used to it, Hakai. Undyne is "touchy feely" in the way that she likes punching people that she likes. But he's probably fine with that, right?]

Excellent! [She holds up a fist.] First--an evaluation of your strength! Show me what you can do to that tree over there! Try to knock it over, split it in half--whatever!

[She tried chomping down a few trees earlier, let's see if this guy can do any worse!]