Killing Spree is better than it has ever been. The radius for target/teleporting is seemingly much smaller as well as static. Meaning it will only target those in the radius where you originally stood instead of targeting from a radius of where you are each teleport and it doesn't seem to target people who cross into that zone after its started. All of that makes it infinitely easier to single target or Blade Furry cleave two targets. It easily does 100-150K with no trinkets popped.
Adrenaline Rush of all the major CDs has the greatest synergy with Shadow Blades. Shadow Blades doubles the CP generation of SS spam and AR further increase attack speed by 20%. Combined with the AR glyph the entire combination dwarf Shadow Dance and Vendetta to the point it is laughable to think the other two are considered burst at all.
The extra energy let's Combat use all the other tools much more effectively as well. BoS being one of them. Let me say that BoS is not better or worst than Shs. Rather they have tradeoffs between each other. BoS used correctly counters kiting tool gap openers at the cost of being a less effective gap closer against everything else like fears or z-axis abuse. Using Shuriken Toss with the Combat's energy regen really helps makeup for a lot of the lost survivability because one is able to maintain recup easily/cheaply, prep for other finishers, maintain crippling and secondary non-lethal, and does all this while allowing you to keep energy at or around 60 for BoS. Also, it produces more damage & CP per energy than SS, which is important because you can use it instead of SS to control and lengthen the time you have 20% bandit's guile.
Finally, 8sec kidneys.