Defensive Psygunner
 Psyker Build - Warhammer 40k: Darktide 

This is a personal build that I thoroughly enjoy for being safe and consistent in all situations. It uses Peril more as a defensive resource so you can guard whatever ranged attacks come your way with the force sword. Additionally it maintains Warp Charges without any hassle via the Accatran's Mk VId Recon Lasgun's obsurdly high firerate and Kinetic Flayer. Here's my logic for the build:

• Essence Harvest will proc regularly due to Kinetic Flayer and Psychic Communion, giving you steady and consistent toughness regen.
• Inner Tranquility allows you to guard more things since your warp charges will reduce peril buildup for blocking.
• Psychic Communion is great for maintaining charges without brain bursting regularly so you can focus on the actual fight instead of resource management.
• Kinetic Deflection is the real meat for this build since it allows you to block significantly longer with your sword.
• Kinetic Flayer is great for HVT burst since you can effectively guarantee a proc with the lasgun. Additionally it maintains charges since you can time the cooldown relatively well with your warp charge timer.
• Kinetic Barrage is here because it's the best solo perk for this build. You don't benefit that much from having the ult up more or soulblaze, so having faster brain bursts is excellent. I personally use the ult as a “get off me” tool and for reloading, but I also use it to get 5 or 6 brain bursts off quickly to nuke a BoN or Plague Ogryn.

• I use the Force Sword with Deflection of course for the ranged protection and I chose Slaughterer is best in slot IMO. I find maulers and armored elites to survive often, so I use the 8% elite damage to prevent that.
• The Accatran Mk VId Recon Lasgun has a STUPID rof that all but guarantees a Kinetic Flayer proc so I use it for killing specials/elites quickly and use it normally for trash clear. The bonus to unarmored enemies is to help reduce Kinetic Flayer procing on a trash mob so you can keep it for an enemy who needs it. Infernus + Head Hunter is good.  That's all.
• The Curios I went with are pretty basic. The only things worth mentioning are Block Efficiency and Tox Gunner resistance. Tox Gunner resistance is because I hate gunners.

I hope this guide is helpful. If anyone has criticism for the build, I'll gladly listen. I'm still newish to the genre and learning myself.