Victor's 'Bubble Double-Barrel Destiny'
 Psyker Build - Warhammer 40k: Darktide 

Another build that took a bit of doing to 'get right'. Wanted a build that used the Double-Barrel Shotgun on Psyker, because guaranteed crits is pretty dang good on top of them being able to fill the range gap easily when needed with Brain Rupture. I decided I also wanted a knife on it too, because I already use, so many greatswords, and so many duelling swords, and even a chain axe here and there. But while I use the knife on Gandalf, I don't have a build that does on Victor, so wanted to have one that married these two ideas together.

And this is what I came up with. If one wants to equip a Duelling Sword on this, they can forgo the two points that get one over to attack speed and instead take Aura plus whatever else one wants, but the knife just doesn't feel good (at least one meant to deal with armor) without the added attack speed to ramp up Uncanny Strike/hit more crits and weakspots. So I 'force it in' to the build, and I think it finally 'made it all work' for me.

Main thought that solidified behind this set up is 'ALLL the DoT!', well, if I wanted ALll of them I'd use a Recon Lasgun for fire then a bleed knife, but one can get what I mean. Bleed the wave with a Shredder grenade amount of bleed every time True Aim is active, fire off more shots if desired to keep thinning the wave/stack up peril (24% peril per reload, it's pretty quick at getting up there even with just Surety of Arms), then go about stabbing everything to stack up another true aim and deal with any of the bigger targets that survived your onslaught. Perilous Combustion also procs flame on any Elite/Specialist kill, which then spreads through out the wave with wildfire, easing your breakpoints on the Combat Blade for light attack strings quite helpfully, allowing you to slide through the wave slaughtering everything as you go. Light attack string the wave (or light heavy string if you're feeling spicy), heavy/push attack string any armored/large target for that nice big poke. Pretty simple, but rather effective, with Riposte helping make up for the fact you aren't running any crit beyond the 5% node. 

Said choice being made to not run Prescience as I need the points to get to Lightning Speed, and while I'd adore Aura as does everyone, it isn't NEEDed here, where the build without Surety of Aim can't generate Peril off of like anything, and Perilous Combustion without Wildfire just never feels good to me. Depending on one's values they can easily change it, but this build very much needs the wave clear help of soulblaze hitting everything when it comes to mixed hordes, so this has 'everything I value here'. Thus, I take Seer's Presence, because this aura plus CDR on curios is roughly 9 seconds off your bubble, bubble lasts 25 seconds and gives you a buff for 5 when it ends, leaving you with 1 seconds between bubble casts assuming it didn't get 'popped'. Sure, that will happen, but with strategic placement and picking your battles more often than not it can survive long enough that you won't fall over during the moment's it's not active, I've played Assail Bubble Psyker enough to know this. As such, this is how I 'make everything work'.

Beyond that, Disrupt Destiny makes up the different, with more crit, headshot and damage in general, on top of that needed toughness regen in between bubble casts. It + bubble is how I get away without Quietude, though neither of the two middle talents would help much anyway given you don't generate peril to often with this build besides reloading. Hiding behind Kinetic Deflector with the knife is amusing though, and very helpful in a pinch if you find yourself stuck in the wave for whatever reason. The Double-Barrel is basically a grenade in your back pocket one can use to melt the wave with True Aim, and that's how I tend to use it if ever said wave feels to 'thicc'. Flame from the kills you generate thin it more, and going after armored targets makes more flame that melts the rest, with Kinetic Flayer helping leagues in terms of creating 'kill cascades' with special kills and otherwise dropping armored targets faster. Otherwise BB is mostly used against gunner walls when nothing's between you and them, the occasional special, and snipers, or if one wants to pre-charge just to do two casts to get one's peril up for Warp Rider/One with the Warp. 

You got options here, it's not 'stellar', but it gets good use out of the Double-Barrel and makes it feel great, while otherwise functioning on it's own. A solid novelty, as a lot of my builds are, and if you ever wanted to use said shotgun on the Psyker, I wholly recommend it.