2.5-4% Bonus Critical Chance on Chained Hit. Stacks 5 times.
Hitting at least 3 enemies with an attack, increases your damage by 24-36% for 3 seconds.
2 Shots on Primary Critical Hit. 2-5% Ranged Crit Chance.
Gain between 3.5-5% and 14-20% Critical Chance based on current level of peril.
Overview
This is a high-DPS sniper build for the Psyker, using the the Electrokinetic staff's primary attack to quickly kill any target with virtually-unlimited range. Most of those attacks will be doubled by the Surge blessing due to the build's high crit rate. Scrier's Gaze with Warp Unbound allows you to continue spamming attacks for 10 seconds after reaching 100% peril, during which time you'll have the full bonus from Warp Nexus, Warp Rider, and One with the Warp. Due to the high crit rate and attack rate, you'll also have high uptime with Empathic Evasion to automatically evade ranged attacks.
It's worth noting that this build requires good aim to reach its potential. You want to be aiming for weakspots whenever possible, with the exception of scab maulers, who have flak armor on their torso but carapace on their head. Aiming center mass is generally fine too, especially at long range, but you'll do significantly more damage with weakspot hits against most targets.
I recommend the Devil's Claw sword for efficient horde clear and defensive parry to counter ragers and monstrosities (or anything else that's giving you trouble in melee). Mk IV Claw is my favorite since it has spammable strikedown attacks for single target, but use whichever you like best. Any melee weapon with decent horde clear can work also. Duelling sword and combat blade are good options if you want better mobility and crusher DPS, at the expense of horde clear speed. Force greatsword is a more balanced option with good crusher DPS and good horde clear, but gives up the defensive utility of Devil's Claw parry. Despite not being a true "melee build," it still has Scrier's Gaze + Disrupt Destiny and can perform better than the average Psyker build in melee combat.
Calculations
Minimum crit chance: 7.5 (base) + 21 (staff 80% Crit Bonus) + 5 (staff perk) + 5 (Surge blessing) + 5 (Warp Nexus blessing) + 5 (Crit Chance Bonus node) = 48.5%
Maximum crit chance: 7.5 (base) + 21 (staff 80% Crit Bonus) + 5 (staff perk) + 5 (Surge blessing) + 20 (Warp Nexus blessing) + 5 (Crit Chance Bonus node) + 20 (Scrier's Gaze) = 83.5%
This is without including True Aim, since it's hard to calculate the exact value there. Note that because Surge blessing launches another projectile, weakspot crits will give 2 stacks of True Aim to fuel even more crits.
Electro staff primary attack deals roughly 2-3x damage on a crit, depending on enemy armor type, and even more on a critical weakspot hit. You can Inspect the staff in your inventory and View Attack Breakdowns to see the exact numbers. Its only notable weaknesses are carapace and unyielding armor types, but the secondary attack deals decent damage against those types.
Gameplay
Against hordes: melee (light attack -> heavy attack)
Against specialists/gunners: staff bolt, or Brain Rupture (outside line of sight)
Against reapers: staff secondary attack, or Brain Rupture (outside line of sight)
Against crushers: staff secondary attack, or Brain Rupture
Against bulwarks: staff secondary attack, or Brain Rupture, or melee (parry -> heavy attack)
Against maulers: staff bolt (torso)
Against ragers: staff bolt (weakspot), or melee (parry)
Against other elites: staff bolt
Against Beast of Nurgle: staff bolt (weakspot), or Brain Rupture (if weakspot is not visible), or staff secondary attack
Against other monstrosities: melee (parry), or staff bolt (weakspot), or staff secondary attack, or Brain Rupture
If your peril starts to reach 80+% during Scrier's Gaze, you'll usually want to quell down to at least half to avoid reaching 100% and ending Gaze too early. You have overload protection from Warp Unbound for 10 seconds after reaching 100% peril during Gaze, but you lose the +20% crit chance upon reaching 100% peril and enter the "lingering" phase. Quelling also allows you to stay in Gaze longer and stack up the damage buff that continues during the lingering phase, providing up to +30% damage if you can go 30 seconds without reaching max peril. In practice you won't get the full 30% most of the time, but it's beneficial to extend the Gaze duration if you have time to quell during combat. Quelling will also restore toughness through Quietude.
It's possible to animation cancel the staff primary attack by pressing your quell hotkey between attacks. You can reach silly amounts of attack speed if you master the timing for this, but you'll skip attacks and end up with a lower attack rate if you screw up the timing. I can't be bothered to do this, and the build already does enough damage to top the scoreboard when played well, but the option is there if you want to go full tryhard mode.
It's also possible to animation cancel the staff secondary attack by swapping weapons (aka "QQ" canceling) after unleashing the charged attack. The target will be stunned for a shorter duration, but the final damage spike will happen instantly on weapon swap. This is worth doing in situations where you value the increased DPS over the longer stun, for example during boss fights.
For PC players, I recommend the FullAuto mod to save some strain on your trigger finger: https://www.nexusmods.com/warhammer40kdarktide/mods/87
Skill Tree
Due to the high crit rate and attack rate with the staff bolts, Mettle handles most of the toughness recovery for the build, with Quietude and Disrupt Destiny as supplements. You can path through Battle Meditation instead of Perilous Combustion if you prefer. PC doesn't reliably get value without another source of soulblaze since you need more soulblaze stacks to deal significant damage and the PC radius is small, but if you have another Psyker on the team to stack soulblaze or you kill multiple elites near each other, the damage can be quite good. Battle Meditation only quells 1% peril per kill on average, so I prefer to gamble on PC doing something useful rather than get the trickle of peril quelling from BM.
The build can either take Brain Rupture or Smite. I prefer BR, but pick your favorite. Don't take Assail because you want the Psykinetic's Aura node that's only accessible from BR or Smite.
Channeled Force and Empyric Shock might seem like they'd be perfect for this build, but in practice I think there are better places to spend points. CF requires you to full-charge a secondary attack every 5 seconds if you want the bonus, which is cumbersome and might even be a net DPS loss since your primary attack is better than the secondary against most targets. ES is good against bosses, but most enemies won't survive 5+ hits for you to get value from the damage bonus. It might be worth testing if ES gives better breakpoints against some targets, but I haven't done that research. Perilous Assault is basically a point tax to get either of these nodes as well, so I've chosen to skip them.
Seer's Presence is generally the best aura for Psyker, and especially for this build since Prescience would cost an extra point. Higher uptime of Scrier's Gaze is more damage and more peril management. One with the Warp and Empathic Evasion are the core defensive nodes of the build, so you definitely want both of them.
Scrier's Gaze is a huge force multiplier for this build and is recommended for Auric Maelstrom and below. With that being said, the build can work with either of the other abilities. If you use Venting Shriek, take the Creeping Flames upgrade. Telekine Dome (aka "bubble" shield) is popular in Havoc missions and is probably the optimal pick there unless you already have a couple on the team. For Scrier's Gaze upgrades, Precognition is preferred for melee/gun builds, but this build would max peril too fast to get value from it. Reality Anchor makes it easier to prolong Gaze for maximum benefit. Warp Unbound is obviously required to avoid constantly blowing yourself up, and also lets you get max value from the various peril-based buffs.
Disrupt Destiny is the clear winner for keystone. Lingering Influence versus Perfectionism is down to personal preference; I feel like I have better uptime on the buff with Lingering, but if you can maintain your stacks with Perfectionism then go for it. Cruel Fortune is optional with Lingering Influence, but pretty much mandatory with Perfectionism; you could drop a +15 toughness node for it.
Warp Rider is a mainstay of high-peril builds and is especially good combined with Warp Unbound. I spent my last couple points to get Solidity for better quelling, which translates to less downtime during combat and better Scrier's Gaze uptime, but you can spend those points elsewhere if you want. If I were to skip Solidity, I'd grab one of the following with those 2 points: Lightning Speed, Anticipation, or Empyric Shock. Without Solidity, Scrier's Gaze will typically end faster too, which means you're not getting as much value from Endurance and can move that point elsewhere if you want.
