Space Jesus (Voidstrike)
 Psyker Build - Warhammer 40k: Darktide 

"Nobody fucks with the Jesus"

Disclaimer: This build is sweaty, and a lot of text for those that want to read the fine print.

After a lot of time with the Havoc meta for Psyker (Bubble, Inferno), I decided that I wanted to try to make the Voidstrike work in Havoc since I've only ever seen one Psyker using it and he was given some shit for it which was lame. But it's not easy to figure out, and it's not easy to play either. I haven't tried every combination, but I've tried a few and so far this works best for me. 

The main drawback of the Voidstrike is its cast/charge time to release a fully charged bowling ball of hatred. To compensate for the long charge time, at first I took the Warp Flurry blessing, but after some experimentation and practice, I just learned to live with the long cast time and opted for the additional crit from Warp Nexus, as this can allow you to reach borderline heretical levels of crit. The really important blessing is Surge, since it both gives you more crit, and doubles your damage on a crit. Also experimented with using dump stats on the staff but the difference between 60% and 80% on charge rate is laughably negligible.

Perfect timing is a nice general damage boost on a high crit build, and Malefic Momentum gives you a nice damage boost whenever you need to swap between melee and ranged, which is often at critical moments. Perilous Combustion combined with Souldrinker gives you even more crit with a fairly high uptime in enemy-dense Havoc, or Auric HISTG/Maelstrom since it doesn't matter who kills the enemy that's burning. Plus it makes up for the lack of other defensive talents quite a bit. True Aim gives you additional crits, which I believe can guarantee a crit every attack if you cleave through several heads with one fully-charged attack. Scrier's Gaze (SG) then boosts your crit even higher, as well as crit damage, finesse, and overall damage. Then Disrupt Destiny (DD) layers on even more damage, finesse, and crit damage. Now your Voidstrike can one shot a Crusher on a crit. At max peril, with Empyric shock and SG active, you're at 73% crit. Those are pretty good odds. 

So, scenario time: Say you're at zero peril and a Rotten Armor party is stomping over to you. I would start out by peppering a crusher with a few light attacks to build peril for both damage and crit , and apply the debuff from Empyric Shock. This only takes a couple of seconds to reach max ES stacks. Then charge your first big hit and aim for the head. At this point it probably won't kill, especially if it isn't a crit and DD isn't stacked. But it will stagger, and it will stagger everything around it too. Which adds a nice bit of utility to the build, and eases the strain of the long charge time by delaying approaching elite packs. Plus you can help teammates out of a bind by smacking and staggering an elite in the head from across the room. Keep launching balls and retreating until your peril gets high, maybe even 100%, then pop SG and start really laying in. Quell before you reach 100% once, twice, or three times before it becomes inefficient depending on how much danger you're in, and then once at 100% peril, launch as many bowling balls as you can before Warp Unbound ends. Chances are pretty high that SG is within a few seconds of being ready again if it isn't already to repeat the cycle (but just pop it right away for the buffs). 

Another important facet of the build is to try to use assail when at full peril. So if the greater danger is a horde or a group of ranged, rather than elites, then take advantage of max peril to kill them all. 

Also note that applying Empyric Shock becomes optional once Gaze or DD are stacked highly, because it'll just be overkill damage then. But you'll still want to apply it to bosses most of the time, and it helps with killing ranged/specialists quickly.

Which is a drawback of the build. None of the staffs really excel at boss damage. Melee and gun psyker are better in that department. I personally like Inferno the best as the dots can do respectable damage over time, and the others are a bit more skill and RNG-dependent. For bosses, when using this build, I primarily focus on keeping Empyric Shock stacks high while peppering weakspots with light ranged attacks, and only if a good opportunity presents itself, like the boss is staggered, will I fully charge a bowling ball. But, if you do crit with a bowling ball on a Plague Ogryn's or Spawn's hard to see face, then it does a juicy amount of damage. Plus, you can free someone from a Beast of Nurgle by hitting its weakspot on the back. Also, I'll generally switch between ranged and melee if I'm tanking the boss, since you might be better off using melee to be able to block. 

For melee weapon choice, I just went with the deimos as its damage and control are great for short melee engagements where your goal is to get back into fighting at ranged. And it's mobility is solid too. But in longer engagements it works well, and taking deflector helps a lot without bubble. It's horde clear isn't great but it's not terrible, so it's a good match IMO. You could pretty easily swap it out for another melee weapon though and be fine. 

So, this build is Havoc tested up to 30 currently, into Rotten Armor, and performs well. Just to point out that it's effective, I top both melee and ranged elite kills most of the time. I even clutched a pretty big section of an Auric HISTG while fighting multiple bosses with an earlier variation of the build. So it's hard, but can survive alone. 

After hitting 40, and practicing in Havoc for several more months, I got confident enough to start experimenting with builds like this. Plus, using the Inspect mods allows me to check other team's builds to ensure that what I want to play will fit into the overall team comp well. Which is pretty critical IMO. This doesn't really fit into every team comp. 

Chances are that players will still prefer you were running Inferno and Bubble, and chances are that it would be stronger. 

But if you feel like using the Voidstrike sometimes, this is for you.