(Menacing) "Do you wanna have a bad time? Do you wish to have an unfortunate experience? I ask if you are capable enough to engage in a terrible experience for yourself and I being the cause. I, Sans the Skeleton, wish to ask if you comprehend the fact that I will give you an unfortunate time due to the fact that you ended the lives of whom I care."

(Say anything you want for the next two. Just make sure they're relevant to Sans and his personality.)