Blaze Bake
 Psyker Build - Warhammer 40k: Darktide 

This build gives the tools for virtually every situation and is highly adaptable so you're never left unprepared or wanting during PUB Quick matches.

Equipment: 
Blaze Force Greatsword: Covenant Mk VIII: This is a great addition to the Psyker took-kit.  This greatsword is useful for hordeclear, elites and specials and it has nice reach for kiting and striking. The Mk VIII has become my primary for this build.

(Alternate)Deimos Force Sword: The purpose of this build is to be able to always be useful whether it's for hordes, elites/special, catastrophes or bosses. You should never be caught without some way to contribute toe to toe.  Of the one handed force swords the Deimos works to this end best. It's pattern is good for chaotic horde melee and charged it hits even the most heavily armored like a truck. For perks I prefer Carapace and Maniac with Deflection and Unstable Power.

Inferno Force Staff: IMO the inferno staff is a must have for higher level quickmatches. The AOE Dot n stagger CC is extremely useful and effective.  Smite might be more effective CC but it's only marginally more effective.  Inferno IMO is more useful and keeps your damage high. Previously I was using Warp Nexus and Flurry, but I've found Penetrating Flame and Blaze Away to be superior.  The extra kick is noticeable and specials and elites pop faster more consistently. With this set up I don't need to rely on Brain Rupture as much which is nice when the tough guys are mixed in with the trash.  The enemy debuff helps the team clear the room as well. 

Skills:
focus on toughness and toughness damage reduction nodes top half.

Quietude/Warp Expenditure/Battle Meditation:  Generate toughness building or quelling peril which is a constant. If you can work in soul stealer that's nice too. I opted for other choices. 

Brain Rupture / Kinetic Resonance / Kinetic Flayer:  Since this build uses the Inferno Staff Brain Rupture is a must to be able to reach out long distance.  The goal of this build is to be able to participate in all circumstances.  Not having a long range attack is a burden to the team and Brain Rupture is simply a badass skill. With Empowered Psionics it does more damage and is less costly.  With Kinetic Resonance and activating your ability it becomes a rapid fire head popper for those squads of elites and specials. Don't under estimate this skill.  The icing on the cake is it does YUGE damage on catastrophe's / unyielding.  Pop your shield and then BR BR BR BR.... and watch what happens. This set up allows you to compete with grenades and plasma for boss dps. It makes the Psyker a real asset when they show up so you don't have to just take out the trash while the rest get all the glory.
 

Perilous Assault: I'm finding I miss this when I don't take it. The missions are pressing harder so the quicker I'm ready to strike the better.
Empyric Shock: This is better than it seems on paper and is making all my staves primary attacks useful.

Psykinetic Aura and Seer's Presence for Ability cooldown. Psykinetic Aura is great when elites are popping from the whole team.

One with the Warp: Touchness damage reduction based on peril.

Ability: Telekine Shield / Telekine Dome:   It's just too good not to take.  Venting Shriek is great, especially if your peril management is sketch but it's difficult to justify taking anything but the shield because it's just such a good refuge when you need one and it's a fantastic anchor for aggressive pushing.  It can really help for getting close to enemies in cover to break them and push forward. Sanctuary is a great node to take too.  Very useful.  I've opted for other nodes but you might find Sanctuary to be a better choice depending on style and need.

Solidity:  I like this skill. The 30% quell speed increase works best for my flow.

Kinetic Deflection:  Is a good way to get around the limited stamina of the Psyker.

Warp Rider: Increased damage 20% -  This really is a must IMO

Crystalline Will: One of the new skills.  This allows for Perils of the Warp to take hold without downing you.  I've great peril management but I take this anyway as insurance.  This might be a skill you opt not to take in lieu of Soul stealer or Sanctuary or something else. I believe this skill can be a game changer, however, considering wipes often happen when even one team mate goes down.

Empowered Psionics: I take this because I prefer Brain Rupture to be more powerful and more efficient.