Wakestones can be used to revive yourself. The easiest way to achieve this trophy is to complete the side quest 'Reapers Scorn' at the same time you do the main quest 'Lure of the Abyss'. At the bottom of the Everfall just before you examine the middle there is a chest in the same room near the back. Inside the chest is a wakestone which you need for the Reapers Scorn quest.
Once you complete Lure of the Abyss go hand in Reapers Scorn. The man will use the wakestone to resurrect his son and the trophy will pop.