this is my submission for mod :P

simple. have the shop keeper appear behind them and say (for the purpose of this his name is josh)
"That josh was the worst"

yes but they would kill him too. its not like they listened that much

Then just give him infinite hp. I did that, they chose violence for a bit. But soon they stopped. Off course they tried to kill the next shopkeeper but I just had it be a silver dragon pretending to be a human. Best part was lore supported that

too late for that anyway

Oh, ok. Sorry

Have him be lev 30 with shape change and he could become a tarasqe

its is too late for me too do that tho

Then do it next time

yup... thats the plan