For 4 seconds, gain 30/40/50% Durability that increases by 10% each attack, up to 80%. Then, strike the current target for 250/400/650 () magic damage.
Combat start: The Sentinel with the most items (ties broken by highest Attack Speed) gains a Shield that grants stacking Attack Speed. When it is destroyed or expires, it bounces to the ally with lowest percent Health and renews. The Attack Speed bonus persists between Shield bounces.