As for people talking about the electrical trap it comes from the stormreaver. He calls a lightning something or whatever and it hits the trash. It does not matter if that trash is at full health or close to death, the trap will go off either way. Although, I can say that his trap does not hit all the trash, it only hits some, not sure of the number. But the trap can come off any trash mobs(not the dragons and giants), so you have to be careful when you are around them.
Also the order does not matter as long as crystal is 3rd
Also I seem to be late, but congratz on the completion