This build is aimed at higher levels of Infinite Archive. For the lower levels I run my usual dungeon trash setup, which is combination of magma 1-piece, spaulder, crimson oath and PA with Vateshran. Just be careful with the Red Incarnate dude, you have to roll dodge as those ticks on Arc 3 plus can eat you.
Reducing damage in later stages is key and allows your partner to build more into DPS, where this build comes out. This build can work with any class, but the NB has easy access to minor cowardice through Power Extraction and if you can increase the length of your buffs and debuffs, this can become quite significant over time. Kynmarcher is also a nice choice in trash, as you will get hit a lot and grabbing buffs will apply quite a few nice debuffs to the crowd.
The Vateshran shield is key for resource management, as you will have to time when to hit it, and then hit Power Extraction for debuff. Vateshran also applies Major Maim, so this is a great approach to get damage down and if you lucky Major Cowardice is the debuff applied. This nerfs the trash damage quite quickly giving you some room to breathe.
Tweak it that it works for you. The DPS with you should make sure to slot some synergies for you and if not, don't use Harmony, use Infused. I ran this mostly with a Templar, so spears were regular enough here.
The traits on the items you can also swop around if you are a Nord, as you might need that much reinforced, but use level you are comfortable with, I usually aim for a minimum of 27 500.
The CP I have buffed for shield to be more o shit rescue options. From the Brink is not a bad shield and buffed by Bastion and if you grab some shield buffs, this becomes a great tool in a squeeze.