(UPDATED) That’s Using Your Noggin
 Psyker Build - Warhammer 40k: Darktide 

This build originally started as me trying to brute force making “Crystalline WiIl”  one of my primary sources of damage. Frankly it just isn’t strong enough. However! I believe I’ve found a build that has good synergy with it. I know most people regard it as a “noob trap” or “meme” but i believe it can be an effective tool in your kit if used smartly. Remember, even if you kill just one elite with it, you’re good! You got to hear your panicked Psyker scream (lol) and then all of the other human sized dudes around you either died or got knocked on their ass. (Seratonin is no purple bar. Cortisol is purple bar)

IMPORTANT NOTE: Exploding takes practice, can’t just waltz into a group and go boom, you will die before you detonate. 

ALSO: it has damage fall off. Bear that in mind.

With a primary focus on melee, it is very easy to hang out in critical peril without fear of overloading thanks to Assail. If you overload on accident with assail a lot you can probably just hang out around 80 and the damage shouldn’t change too much. 
I just do basic math: Assail generates 10 peril always. So if you’re under 100 peril, you can throw at least 1 dagger (throwing while at 100 cracks your cranium).

I use Assail solely for utility (keeping peril up) and as the only trigger for Noggin Nuke. 

Ultimately, your main damage comes from the passive talents. Combining the manageable peril control from Assail with Warp Ghost (-80% passive quelling) you can achieve excellent uptime with:

1. Warp Splitting (100% Cleave)

2. Immaterial Focus (stun immunity)

3. One with the Warp (33% TDR)

4. Warp Rider (20% base damage)

5. Unstable Power (Sword blessing 20% strength)

Insane amounts of value as long as you play smart with assail.

IMPORTANT NOTE: Sploding removes all peril which means all of the above buffs go bye-bye. I try to ensure that I have reserve assails before triggering so I can quickly get my peril back up. Otherwise, things might get painful. Also if you try to quickly back-to-back blow up, you’ll find yourself out of Assails and pretty weak until the recharge.

i personally don’t invest into any assail buffs, but the quicker refresh is useful.

Whack baddies with sword, manage peril and pop your pinhead when things get dicey (This doesn’t take much as you will usually be close to critical peril). Pistol for monstrosities and ranged turds.

Don’t run with scriers. I like shield :)

You can sub out the wound curio for more toughness. I run extra incase I get unlucky with brain blast :(

Thoughts from weekend testing: 

Honestly, blowing up your head is very risky and so far seems very bad in Havoc. As much as a little guy like me dreams of it being a primary source of damage, that just isn’t going to happen. Playing smart with it actually feels alright in Auric.
If they added instant overload to Crystalline Will (or even just halved the time of the overload animation), that would be nice.

Also I discovered that the headsplosion damage isn’t considered a “warp attack” so it doesn’t benefit from:

Penetration of the Soul - 20% rending on warp attack.

This made me so sad that I made a Fatshark forum account just so I could ask why it’s not a warp attack. (20 views and 0 replies as of time of writing this lol). Just having a little armor pen on it would be helpful.

So it goes without saying that the noodle nuke is very bad against carapace and it is absolutely useless in Rot Armor modifiers. 

Crystalline Will is NOT A MEME and I have HAD IT.

Might make a video. Never recorded gameplay in my life.

Have fun :)