Akkhan's Leniency

Akkhan's Leniency is a Legendary two-handed flail in Diablo III, added in patch 2.4. It requires character level 70 to drop.

The special affix boosts the damage of  Blessed Shield by 15-20% per stack, earning one stack the first time an enemy is hit, per bouncing shield, every cast. Each stack has its own 3 second duration which expires separately from the others, with the number of current stacks displayed as a buff.