Is there a way to determine which boss appeared during the bank robbery mini world change?

Question

These are the notifications we may encounter during the MWC bank robbery. One appears on the world board and the other shouts Towncryer in Thais.

Is there a way to determine which boss appeared during this MWC without checking every possible spawn point?

Answer 1

The fastest way to check is to speak to the bank NPCs.

If the bag with stolen gold has not yet been handed in, the world board will display the "Several banks..." message and one of the NPCs will respond to hi like this:

Naji / Suzy: HELP! We have been robbed! I can't give you any gold until the robber has been brought to justice or we have received a compensation from the king. I think the robbers ran towards the Ancient Temple.

Rokyn: Those Shadowthorn elves have gone too far this time! A whole crowd of them stormed the bank, and even though I fought them back the best I could, I was outnumbered by dozens. ...
Rokyn: I fear the gold is gone, kid. The merchants here will help us pay the debts, but not before tomorrow. Unless someone finds and kills those elves I can't do anything for you.

Eva: *Sob*... I'm still in shock. A man just came up to the counter and he... he... forced me to fork over all of the gold. I'm really sorry, but I can't serve you right now. ...
Eva: The queen has been informed, but it won't be until tomorrow that she will compensate the losses. Maybe you can help find the robber? He ran off into the direction of the ghostlands.

Finarfin: HELP! We have been robbed! A whole bunch of no-good dwarves stormed the bank and took all of our gold. I fear they hauled it into the Kazordoon mines. I can't serve you until we have gold again.

Which bank robber has spawned can be determined by which NPC responds differently. Note that the robber could have been killed already, and the bag might not have been returned.

When the bank robber has been killed and the bag has been returned, the message on the world board will disappear. Then, the NPC of whichever bank was robbed will respond to hi differently until the next server save:

Naji / Suzy: The filthy bank robber has been brought to justice and almost all gold has been returned. We are back in business!

Rokyn: Ha, those lousy elves got what they deserved. All the robbed money has been returned to the bank. What can I do for you?

Eva: I can't believe it - the bank robber has actually been caught and the gold been returned. I'm so relieved. How may I serve you?

Finarfin: Those dwarven scumbags have been caught and the gold from the bank robbery was returned. I can fulfil your bank business as usual.

If you see one of these messages it's too late, a bank robber has been killed and another one can't spawn until after the next server save.