Throw the knife, take out its wings so it can't escape.

You deftly flip the knife in your hand, hurling it with about as much accuracy as could be expected from cutlery but nonetheless managing to punch the empowered blade through the base of the demons wing. Needless to say, it is not pleased.

"YYYYAAAAA-!"

You dearly wish you could silence its piercing cries but your initial attack left you weaponless. Unless...

You appraise the solid book resting against your side. That could work. The imp's eyes go wide as you approach, the enormous journal held up as though you were about to kill a particularly loathsome insect. It skitters backwards, over your fallen knife, while brandishing its stinger at you. You really didn't want to get stung by that. You see the imp's eyes glance to the side at the bookshelves and you read its plan on its face. If it got into the shelves it would be an absolute bitch to kill the thing without getting stung. You go for the kill, bringing the book down and hurling it the last foot to avoid proximity with that despicable stinger.

Unfortunately, this demon seemed a touch more intelligent or at least a touch more experienced than previous imps you'd encountered. It feinted, seizing the knife and hurling it at the shelves, using the momentum to propel itself out of the path of the book. You hear a crash to your left but continue tracking the imp to your right. You growl low in your throat, your anger entirely your own as you block the Goddess for fear of any distracting lust spikes. This was not the time for imps to grow brains.

"P-please... merciful lady..." The imp cowered and sniffled, looking up at you with wide, teary eyes, "D-don't kill me..." It's such a pitiful sight that you almost hesitate before smacking the hellish thing senseless and bending down to grab its stinger by the base. Now where was that-"AUgh!!"

You spring forward, the sudden thrust of something thin and squirmy into your virgin bum nearly making you brain yourself on the stone wall. You straighten in a heartbeat, the awful wet and squirmy sensation not letting up despite your sudden movement and clenching of your buttocks. Your hands slap and claw at your rump, the thin fabric of the dirty nightgown hindering your efforts as whatever it was slid inexorably deeper despite your best efforts.

After panicked seconds you finally get a grip on the thing, which was even more slippery than its writhing's in your asshole led you to believe. Renewed panic sets in as you feel the end of its tail flop against your palm, your **** grip the only thing preventing it from sliding further. Your lack of experience made it hard to gauge exactly how long the thing was in its entirety, but its writhing seemed to fill your entire belly.