Karen Mode Psyker Havoc 40
 Psyker Build - Warhammer 40k: Darktide 

First, to cover the weapons of this build, there are 2 choices of weapons I would recommend.  The first weapon is the Catachan Mk III Combat Blade and the second is the Maccabian Mk IV Duelling Sword.  Both of these weapons offer high mobility and single target damage which compliments this build perfectly.  The Maccabian Mk IV Duelling Sword is already covered in this build and in the video so I won't go over it again except by stating that if you don't like Thrust then you can swap to Precognition instead for more constant and rapid damage.  Both work fine.  The weapon I want to cover is the Catachan Mk III Combat Blade since I show it in the video, but it isn't possible here unless I talk about it.  For that weapon, the perks I would use are Maniacs and Carapace to cover the main threats you will face to cover aggressive enemy types that will push you into melee.  For blessing, I would suggest Precognition and Uncanny Strike since those will ensure you deal high consistent damage to enemies forcing you to dodge and move around.

The build for overall gameplay style is to use Assail and Equinox Mk IV Voidstrike Force Staff to engage with all enemies from ranged and depending on what armor type they are.  If anything starts to get close, you use Venting Shriek to push them away or apply massive amounts of Soulblaze to the horde.  With the build setup and on Havoc 40, you will constantly have stacks of Warp Siphon and constant application of Psykinetic's Aura meaning you will have high cooldown with high ability spam.  This allows you to keep constant damage and most horde controlled from the DoTs you will be applying.

One thing this build is tight on is space for talents meaning that it's hard to flex anywhere, this means if gunners or ranged enemies are an issue, then another Psyker with Telekine Dome or Vet with Smoke Grenade can help mitigate the ranged attacks while you deal with the ranged enemies.

If you want to sacrifice One with the Warp and Quick Shards then you can build into Empathic Evasion and Anticipation which will give you a much better ranged defense and really good dodges.  This is up to you and your personal preference or if you have another class to help mitigate ranged damage from enemies.

I hope you guys all enjoy the build and have fun with it!