It might be a form of cover but not cover directly. Maybe something to the extent of giving a shield to another player which when attacked nulifies damage and gives the hate to the DRK. Since the full animation looked as if the shield broke after 1 strike, so it could be a form of enmity removal from a target that also blocks incoming damage.
Watch the gif again, for a "cover" it doesn't really seem to last long, DRK uses it on target, target is hit and the shield breaks.
