Randomly after losing the lvl 25 gladiator quest I got revived and went in and got a buff "The Echo" along with the flavor text over it "The power of the Echo flows through you. You take less damage and deal more damage." as well as the chat text "The Echo grants you strength beyond your limits!"

There was no timer on it, it lasted until the mission was completed. Is there any specific cause for this or is it just something that can sometimes happen if you lose an instanced quest? Have lost a few before and never seen it.