Fires on a hit with the weapon of an active item set worn by one of the fighter classes. It cannot be cast or aimed.
Proc chance by set tier: 4% at tier 1, then 6%, 8%, 10%, 12% and 16%.
It does bludgeoning damage. The number of dice is set by the set's tier: 2d6 at tier 1, then 4d6, 6d6, 9d6, 12d6 and 15d6. Your own level does not change it.
It bursts in a 5 metre sphere where the blow landed. It needs line of sight and never hurts the wearer.
Creatures further from the centre are hit slightly later.