Liko with the help of Rosskag goes over Stamina Nightblade PvE DPS'ing in the video below. Make sure to support Liko at his Patreon! And check out his website, Liko.gg, a friend of the ESO University website!
This is a 10-second rotation:
Arrow Barrage, Poison Injection, Rending Slashes and Consuming Trap are each 10 seconds long.
The minimum backbar rotation is: Arrow Barrage - Poison Injection.
Usually, you will have to apply the Shades and Barbed Trap every other rotation on average.
The minimum front bar rotation is Rending Slashes - Consuming Trap.
If you have Bow Procs ready, go for it. The rest of your front bar time should be spent spamming Surprise Attack. Incap Strike should be used in a timely fashion, to provide you with the maximum burst. To make the most of it, usually, it will be one of the first skill to be used on your front bar. Then follow it up with re-application of your Rending and Soul Trap as soon as possible, if you haven't already, and also fit in as much Surprise Attack and Bow Procs as you can.
For Maarselok, you will need to Bash once every 7 or more seconds to proc its effect.
Start (setup and the starting burst): Dark Shades - Leeching Strikes - Relentless Focus - Barbed Trap
Part 1 (with incap) Arrow Barrage - Injection Incap - Rending - Soul Trap - Spam - Spam - Spam - Spam - Spam
Part 2 (without incap) Arrow Barrage - Injection - Barbed Trap - Dark Shades - Leeching Strikes (if needed) Rending - Soul Trap - Spam - Spam - Spam - Spam (this last one if you didn't cast leeching) Spam = Bow Proc or Surprise Attack or refreshing Relentless Focus (every three parts)
At 25%, keep up Arrow Barrage, Poison Injection, Barbed Trap, Dark Shades and spam Killer's Blade. In short fights, aim to have DOTs (and relentless focus with 5x stacks, for the new crit damage buff) running one last time, before spamming Killer's Blade until the end.