How does Victor at first respond to the creatures demand? What response does he expect from the creature? What approach does the creature say he will take?

Victor refuses the creatures demand and expects him to back down.

"I do refuse it," I replied; "and no torture shall ever extort a consent from me. You may render me the most miserable of men, but you shall never make me base in my own eyes. Shall I create another like yourself, whose joint wickedness might desolate the world. Begone! I have answered you; you may torture me, but I will never consent."

The creature says that he exact his revenge, inspire fear, and destroy his creator.

Yet mine shall not be the submission of abject slavery. I will revenge my injuries; if I cannot inspire love, I will cause fear, and chiefly towards you my arch-enemy, because my creator, do I swear inextinguishable hatred. Have a care; I will work at your destruction, nor finish until I desolate your heart, so that you shall curse the hour of your birth.