In a campaign I made myself, there is an 8th-level Druid NPC (good guy) that have an item that I want the bad guys to steal (killing him in the way, for dramatization).
My main concern is that he could just transform into a bird and fly away (with the item).
There should be a witness to inform the players that the bad guys took the item. So his defeat should be credible.
Here is the question: As GM, should I just say that the druid is dead, ignoring all the resources that a character of that level has to defend himself?
Or, should I, on the other hand, run an encounter (offscene) with detailed composition of evil forces to defeat him?
How could I elaborate this event?