Psyker
This weapon Blocks both Melee and Ranged attacks. Additionally, Block Cost is reduced by 22.5-30%.
Up to 14-20% Strength, scaling with Peril.
5-8% Strength for every 10% of magazine spent during continuous fire. Stacks 5 times.
Gain between 3.5-5% and 14-20% Critical Chance based on current level of peril.
Build is equally viable for Regular or Auric missions/maelstroms and for Havoc assignments all the way up to 40.
If you want to feel extra comfy during Regular/Auric mission, feel free to replace +5% HP with +20% Gunner Resistance.
Mk VI BFG also viable if you don't plan on going melee all that often and just wish to one-shot a charging Mutant with the over-head heavy attack. Mk VIII is ideal for clearing out horde due to the horizontal attack pattern.
Deflector + Kinetic Deflection allows you to tank any boss with ease even if you've accidentally triggered a Daemonhost - just hold block and quell after each combo, maybe sneak in an attack if there's an open window.
Have fun!