You were an important factor for Nightmare's plan. Whatever that plan was is out of your knowledge but because you're important, Nightmare gave you Killer as a bodyguard for the time being. He told you Killer would be ready by tomorrow.

DING DONG!

You were relaxing in your house, doing a hobby of yours when the doorbell rang. That must be Killer. When you got up and opened the door you were surprised to see Killer in a suit. He had a flower in his between his phalanges and held his hand to you.

"For you!~" Killer joked around.