John Greatsword - Hit Hard Against All
 Psyker Build - Warhammer 40k: Darktide 

Playstyle:

• Melee focused
• Aggressive
• Frontliner

This build are for the bold players who likes to go head first into danger and deal truckload of damage to anyone and anything.
Tailored for "best offense = best defense", keeping an aggressive tactic grants big damage buffs as well as resilience to damage.

You keep "Scrier's Gaze" active for longer by doing weakspot kills ("By Crack of Bone"), each quelling 10% off the peril meter.
Quell with the staff during moments where there are no heads to cleave so it doesn't reach 100% too early to keep stacking 'damage up'.

Prioritize weakspot kills on marked enemies as often as you can to keep "Disrupt Destiny" stacks high.

Staff provides enough utility for sniping and deals big damage against anything on crit.
With "True Aim", you are also  after hitting heads 5 times in melee.

Key takeaways:

• Big weak spot & crit damage
• Efficient horde clearing (Greatsword cleave and special attack)
• Great mobility and evasiveness
• High toughness regeneration and resistance
• Greatsword Mk VI and VIII both viable, pick whichever suits you:
  • Mk VI for some extra single target damage output (the H2 stab deals more damage).
  • Mk VIII for more straightforward attack patterns, less worry about messing up sequences.
  • Hold primary attack when doing a 'push' to inflict big stagger on a single target (has longer reach too), I use this mostly against Pox Bursters (this triggers them too), Crushers, and Bulwarks. Release block immediately after this while still holding primary attack to do a follow-up heavy attack (Mk VIII = hard hitting stab, Mk VI = standard overhead slash).
  • Warning: Doing the big stagger move while at 100% peril will cause overloading!
• Voidstrike and Voidblast staff both viable, same primary fire is good on its own for sniping, as for secondary fire:
  • Voidstrike if you prefer big damage against single target and clearing tightly lined up groups, big stagger against Crushers and even Beast of Nurgle at times. On crit, the 'Surge' blessing literally doubles the crit damage by launching an extra projectile.
  • Voidblast if you prefer more crowd control utility with brittleness debuff ('Rending Shockwave' blessing).
• The greatsword special attack procs "Malefic Momentum", meaning you can stack up to +25% non-warp damage without using your staff.
• Weakspot hits with melee procs "True Aim" too, so you are guaranteed a ranged crit with staff after some swinging.

My choices and why:

• No "Warp Unbound": 10 seconds of no overloading does not bring much utility to a melee-focused build unless you spam with the staff and/or need a safety net to prevent accidental overloads.
• No "Kinetic Deflection": I rarely ever needed to block as dodging efficiency is good enough.
• No "Empathic Evasion": Ranged invulnerability feels too short and redundant with all the toughness talents.
• No "Warp Splitting": The greatsword's does not struggle much in terms of cleave, even more so with special attack.
• Chose "Warp Speed": The 20% speed buff stacks with "Disrupt Destiny" to 40%. Faster movement is very beneficial for keeping up the momentum in melee when enemies are dispersed.
• Chose "Kinetic Presence" as aura: The build is very strong against elites, overall increases everyone's elite-melting potential against groups too. Alternatively, "Prescience" is a good choice too for crit frequency.