+1 to Maximum Endurance Charges
25% chance that if you would gain Endurance Charges, you instead gain up to maximum Endurance Charges
Gain 1 Endurance Charge every second if you've been Hit Recently 
Unflinching is a Notable Ascendancy passive skill for the Juggernaut that grants an additional maximum endurance charge, a chance to gain an endurance charge when hit, and generates an endurance charge every second if you were hit in the past 4 seconds. Additionally, whenever you gain an endurance charge, there is a chance it sets your number of endurance charges to its maximum.