The Assail Assault build focuses on one aspect of a Psyker’s arsenal, the throwable assail darts. In the lower difficulties, you can just about run the entire mission with these, without ever using your weapons. In the higher difficulties, these become an extremely strong part of your arsenal, as you freely change between your weapons and the darts. This build excels at just about all factors of any mission. It clears hordes, its very strong with specials and elites. The only thing you may have a tougher time with is carapace enemies. In these encounters, play it safe, and with your allies. Your role is to eliminate elites/specialists as swiftly as possible. Where the Psyker lacks is maneuverability and could have better survivability, but excels at very high burst damage, killing elites/specialist before they become a threat.
One of the strongest melee weapons for the Psyker, the Mk IV Force Sword is versatile and with comes with some amazing perk combinations.
Deflector is a an amazing survivability perk to have, being able to deflect range attacks, and receives a cost reduction to all blocks makes it very strong. This really shines when your skills are on cooldown and you need to protect yourself against ranged enemies. It is also useful if you need to gain ground against elites or specials. Slaughterer is a great and easy perk to use, getting kills will increase all aspects of your offensive capabilities while using the sword.
For the modifiers, Maniacs or Flak would be good options here to cover many elites/specials variants. Block Efficiency comes hand in hand with Deflector for increased effectiveness. If you don’t like/use Defelector, then use both Flak/Maniac modifiers.
The Trauma staff is a very strong weapon, able to do ample amount of damage to elites and easily clear hordes. The best effect it has comes with charging it up, so if you’re in a pinch, your sword or Assail ability may be best to use.
Warp Flurry and Warp Nexus, while they function differently, very easily build off each other. Warp Flurry relies on consistent and consecutive attacks to activate, and Warp Nexus build off your peril level, the more you attack, the more peril you get. Having both these perks together augment the weapon equally and efficiently.
Since carapace enemies are the only thing that really pose any problems with this build, having that modifier here makes the most sense. Maniacs or Flak for the second modifier, both cover a nice range of enemies.
Curios are really flexible, with only a couple perks that really benefit builds. In this case, Health can be substituted for Toughness if required, but health is still recommended. You will want at least 1 Curio to have 1 Wounds on it, wounds increase the amount of health bars you have. This is beneficial, especially on higher difficulties, as it allows some leeway if mistakes happen, or you get overwhelmed.
Stamina Regen is really important and should be the only modifier you go for one each Curio you use. Block Efficiency is great to have to further extend the capabilities of your melee weapon.