70-100% Rending on Backstab Hit.
12-24% Rending on Enemy Weak Spot Hit for 3.5s. Stacks 5 times.
14-20% Strength for 5s when every pellet in a shot hits the same enemy.
6-12% Critical Chance for each Enemy Hit by your previous attack. Stacks 5 times.
In this build the goal is to rapidly cycle your ultimate, which is stealth. While stealthed any hit will unstealth you and automatically land a crit. Backstabs deal increased damage. "Invocation of Death" allows a 1.5s ult cooldown every time you crit. The knife's base crit chance is higher than most weapons. "Blazing Piety" will add +25% crit chance, "Scourge" will add +30% crit chance, and your weapon's perk will add +5%. The total crit chance above the knife's already high base crit is +60%. This means that even if you are not able to activate one or more of these, your crit chance should always be at or above 50%. Because your crit chance is so high and your damage on dropping stealth is so high, the optimal playstyle is to stealth, land a crit kill on a crusher or other large target, and then immediately begin left click spamming to drop the cooldown rapidly. In optimal circumstances you should be able to ult every 5-10 seconds.
If you wish to play collaboratively stealth can be used to complete objectives, raise allies, and drop large targets without much if any risk to yourself. If you wish to play selfishly, stealth is good for repositioning and saving your own bacon, as well as moving very fast.