If it was another player then then it couldn't have been because Shalltear had managed to kill the one using the item or wounded him to the point where they would have to retreat while leaving her there. Shalltear didn't possess a skill or spell that could cut a level 80 player's health to the point where he needed immediate and long term healing from just one hit.
"No matter what the setup was, if your opponent was a player or players from YGGDRASIL then it wouldn't have ended with you being left alone in that place in your neutral state. Thus a picture forms of someone who's only hope of beating you was using their world item to mind control you, however you managed to wound or kill the one using the world item before the control was complete and forced them to flee while leaving you in that state."
"It is as you say Ainz-sama."
"Well then, there remains only one question that I'd like to ask you Demiurge. Why the Slane Theocracy?"
"About that Ainz-sama, considering that we know for sure that the empire does not possess such power nor the kingdom, geographically the Theocracy is the obvious next suspect."
"Hmm… that definitely makes sense, with the kingdom and the empire out of the picture the only other nation close to us would definitely be the Slane Theocracy.
"Also as I said earlier, thanks to the empire's intelligence network I was able to find out much about the Theocracy's inner workings. Amongst those was a report that they have under their control a special unit like the one Ainz-sama fought in the human village, with the main difference being that this unit possesses items that were reported as 'not of this world'.
Ainz could not help but let out a soft 'aah' sound as the pieces of the puzzle were coming together quite nicely.
"So then let's assume that this unit like the ones we encountered at Carne Village were out on a mission and came across Shalltear. After witnessing how strong she is they resorted to using a world item. However Shalltear sensed the danger and struck a blow against the one using the item, thus causing a draw due to killing or wounding the user."
"Indeed Ainz-sama that is my theory as well, however it is impossible to say if it's really them who are responsible for the incident. But I believe that at this point it is our best lead."
"Hmm, you're right Demiurge, it is definitely worth checking out. Eventually we would become their enemies anyway seeing as they despise non-human races."
"Ainz-sama please send me to dispose of those lesser beings! If they really were the ones responsible for my blunder then I should be the one to handle them! I will turn them into zombies and have them kill their own loved ones and family to see how they like it. Or should I maybe do the reverse and force them to kill or be killed by their zombified loved ones."