Lets do things by the book...

Killing one new player and a pet had been enough to push you into the next level. The Beastmaster was more experimented, she was probably worth even more XP, she might be enough to get you to level three, giving you the power to possess most of the adventurers going through this area. And then the real fun could begin.

You look around, looking for the best mean of attack. To be honest more of your option were easy to beat, especially for and experienced character... however now you had the possibility of possessing multiple objects and it changed everything. Especially since your HP is tied to what you possess, it would be much harder to kill you now, unless the adventurer had ways to destroy everything you haunted at once.

Before your level up the books' speed was barely and advantage considering that their attack and defence were so bad, but now you would be able to swarm your ennemies with them.

Or maybe not: as you went to possess a whole shelf only a few got under your control. Puzzled you looked for the more detailed description of Possesion(I) and groaned internally as you discovered that of course there was a limit to how many object you could possess. It was set at one and a half time your level rounded down though, even if that meant you were limited to three objects for now you would soon become more powerful as you level up.

Speaking of levelling up... The beastmaster was finishing her message and she looked like she was about to go away. There was no way you could let this opportunity slip by. You only possessed three books
but it would do. You threw your hardcover stand-in bodies at her. The amount of damage was ridiculously low but with several of them you could spam the attack fast enough to leave the adventured reeling, unable to fight back.

The beastmaster goes down a lot faster than you expected, she must have taken some damage from the chandelier too. As her body dissapeared you heard the ding signaling your level up and rushed to check your new stats, only to discover that except for your level nothing had changed. It made sense, all your abilities were tied to what you were possessing, and what you were possessing was only limited by your level. There would probably be quite a few other level up before you got a new ability.

For now being able to possess four objects at once or a level three adventurer would have to do. Your options are still kind of limited though. Maybe it's time to go somewhere else? Or maybe you can think of some new ways to use what you have, it had worked well enough with your little ambush... or maybe you just want to wait for the next adventurers and deal with them. The Beastmaster had send a message to her mage friend to ask her to come back hadn't she?