Hitting an enemy gives them 1-4 stacks of 2.5% Brittleness. Debuff lasts for 5 seconds and can have a maximum of 16 stacks.
+5-8% toughness on Chained Hit.
Target receives 10-16 stacks of 5% Brittleness on weapon special hit. Lasts 5s
+4.5-6% Toughness on Close Range Kill.