Battle Chateau Bell Indication?

Question

In the Battle Chateau, I often walk out of a room and find that a bell goes off, announcing an NPC's name. Does this indicate anything else besides a notice that an NPC is being welcomed? At first, I thought it meant that I had to go that trainer for whatever reason, but now I'm not sure.

Answer 1

The bell sound means that a new NPC has entered the Chateau, as you said. You do not have to go to that NPC, but if they are a "boss," you have to beat them to go up in class.

Source: Experience