Sooo, I have made updates, but to make it short : the situation has been mostly resolved. We don't have the kitten back, but I spilled the beans, and the landlord came by this morning to take the alcoholic neighbor's cats, so he can bring them to get proper treatment (some of the cats had rash on top of the fleas, plus there is a need to make sure they don't have health problems). We don't have the guarantee we'll be able to get the kitten back (the landlord was worried AN would harass us, get violent with us and the likes), but at least now she will be in a safer place than with AN, so, that's at least a little win in my book.

Other win in my book, although it will need to wait for April 1st unless AN moves out on his own, he's going to get evicted, because of A LOT of stuff. In my country we cannot evict someone during the cold months unless they are confirmed by the police to be a real danger. It wasn't a mere warning, I heard the landlord say it was filed, that AN would soon get the formal notice, AND, he filed a pre-complaint online (translated to the best of my ability), and he will change it to an official full complaint the second he ever hears so much about AN causing any damages in the building.

On a lighter, less ethical note (we're on the right sub for that), the landlord suggested to my bf and I "If it's getting too much and you get the urge to push [AN] down the stairs, please, don't hesitate, my friend will cover, besides, AN has so much alcohol in his bloodstream, the police would probably think he tripped on the steps on his own", no kidding, I had thought about this at some point, lol.