Armored Flame-Venter for Havoc
 Psyker Build - Warhammer 40k: Darktide 

The main build I run that works for most havoc modifiers (Bubble best for Pox missions). Saving this build before update. Use the move speed with knife to constantly position to best angle to mow down everything with flame staff and venting shriek. One may wonder why not bring Empathic Evasion, however with Anticipation I feel there is more use as I rather be able to dodge more effectiviley than rely on there being enemies right in front of me to proc Empathic Evasion. It also helps much more to get out of bad situations to have an extra dodge with knife to create distance from the Chaos spawn that just jumped on your head.

The biggest downside I've found is when you get caught alone with no help to stagger in melee, you may panic and feel the best play is to spam flamestaff to back the horde up. Unfortunately there is usually that one mf who slips through and gets a hit in spiking your peril to the max amount allowed for Just a Dream : 97%. If you do not notice the spike in time and are actively flamestaffing/ shreiking, it is very likely you will get caught without venting shreik and head pop. If this can be avoided, Just a Dream provides great survivability over long havoc missions where heals can feel very far and few bewteen. Being able to go down an extra time when the director is having a bad day can save a run. 

I am still torn between using knife or the Deimos Mk IV Blaze Force Sword since the force swords allow you to bring peril up quicker to shriek. However, when caught at critical peril after getting swarmed in melee as mentioned before, pushing with the force swords generates peril.. also risking head pops. I almost believe that running Covenant Mk VI Blaze Force Greatsword is worth it over the Deimos since the peril generation on special charge is much greater and takes less time in animation than the traditional force swords. This usually requires bringing a stamina curio though, making Just a Dream that much more important in survivablity. 

Knife has been the most reliable due to move speed of course, and also makes dealing with risk of head pops much easier. Just a dream will keep peril up as range enemies will be searching for you after shrieking each room, so not having the force sword isn't too much of a problem. Bringing the greatsword seems to be the stronger yet riskier option if you can manage it.