You're My Saving, Grace

(12x07 coda/alternate s12) He was so sick of all this back and forth with the Winchesters; he wanted it to be over, to have a little peace for a change. What Lucifer doesn't realize is that peace comes at a mighty high price, and often has some unusual side effects...like sassy little witches and other unexpected company. (May contain some shippy fluff if you squint)