Doppelganger
The next floor turned out to be a boss floor as I saw the waiting area in front of a set of double doors.
Looking through the doors to see what the boss was, I found a rather familiar looking throne sitting in the centre of the room and nothing else around it.
I assumed that it had something to do with the throne where I fought the Succubus Enforcer in.
During that boss fight, it was clear that the Succubus Enforcer was meant as a 'guard' for the throne. So I assume that in this boss fight, I would be facing the one who should be seated on the throne instead.
If I had to guess, the monster might be some kind of succubus royalty or something.
Since the Enforcer was using physical attacks, I suspect that this one might be using seduction attacks instead or maybe magical ones.
We took a quick break, replenished our Mana, checked our gear, activated my [Mind Shield], then stepped into the boss room.