Perk 3: More Surprise - You have 30% chance to do Addon-Critical - Your weapon reload time are increased 30%
Perk 5: Additional Surprise - You gain another 30% chance to do Addon-Critical and another 30% reload time addition
Perk 7: Critical Health - When your armor breaks, each successful Addon-Critical give you 8 life point
Perk 9: Over Critical - Life point is increased to 12 now