"Soul Stealer" Havoc-40 Psyker
 Psyker Build - Warhammer 40k: Darktide 

Role

Midline area-control and attrition specialist with emergency elite deletion.

You are not a conventional melee Psyker, pure boss killer or long-range specialist. 
Your job is to control the shape and tempo of high-density engagements.

Situational Adjustments

The Inferno Staff does exceptional area damage and should do most of the work.
Melee weapon solves survival and single-target problems.

An alternative to Deimos Force Sword is the Maccabian Duelling Sword for coordinated teams.

Duelling Sword is better for maximum mobility and aggressive tempo, but Deimos Force Sword is a better fit for reliable public-group H40 clears, especially because this build uses Venting Shriek rather than Telekine Shield.

1. Deimos Mk IV Blaze Force Sword — completion and clutch optimization
2. Maccabian Mk IV Duelling Sword — speed, mobility and offensive ceiling

The standard combat cycle: Build peril with Inferno → Shriek near critical peril → reposition → resume Inferno casting

Why Deflector? 

Deflector currently:

• Allows the Force Sword to block ranged attacks.
• Reduces block cost by 30%. 

This is particularly valuable because the hybrid talent tree includes Kinetic Deflection. Deflector fills part of the ranged-defence gap.
Together they provide a strong defensive package:

• Block Gunner and Reaper fire while reaching cover.
• Protect yourself while reviving.
• Survive when Inferno’s channel is interrupted.
• Block Rager pressure while dodges recover.
• Cross short exposed areas without a Telekine Shield.
• Stabilize situations when Venting Shriek is unavailable.

Higher Damage Alternative

For a coordinated team where melee survival is not a problem:

• Remove Immaterial Focus
• Remove Melee Damage Boost
• Remove Kinetic Deflection
• Select Vulnerable Minds
• Select Warp Rider
• Select Warp Ghost

Becalming Eruption is Shriek-path modifier that reduces peril generation according to enemies hit.
Creeping Flames is the Soulblaze modifier used for offensive Shriek loop.

Curios

For a confident player who blocks, pushes and re-positions aggressively:

• Toughness
• Toughness
• +3 Stamina (+21% Health valid alternative)

Possible Changes

Seer’s Presence used for team cooldown support. 

For public or less coordinated H40 groups, I would build around:

• Brain Rupture to cover distant specials, Bulwarks and armored targets
• Telekine Dome/Sanctuary for ranged protection and team sustain
• High-peril damage and damage-reduction nodes
• Soulblaze application, spread and sustain talents
• Reliable toughness generation

Tips

For a coordinated team with adequate ranged protection:

• Venting Shriek/Creeping Flames can produce more offensive pressure.
• Telekine Dome/Sanctuary remains the more forgiving and universally useful selection.