Being given a mission as a demon slayer while it's already the middle of the night is never something anyone looks forward to.
It adds a sense of urgency to get it all over with even faster than normal; the race against the rising sun isn't just one for demons, but one for demon slayers as well. who rely on demons coming out to hunt.
All thoughts of "can this just be over already" are replaced instantly, however, once you find none other than the Demon King outside, surrounded by and almost glowing in the moonlight...
Whether his recent more active presence nearby was a coincidence and just chance, or he's looking for something, who knows. Though now, you're wishing it wasn't this way, especially as he walks right up to you, fearlessly in arrogance.
Oh? Another demon slayer, hmm? Unfortunate.