+1-2 Extra Chained Energised Hits and +2.5-10% Impact on Energised Hits.
+7.5-15% Weak Spot Damage. Weakspot Kills also ignore Enemy Hit Mass.
+70-100% Critical Weak Spot Damage.
+10% Critical Chance for every 0.2-0.35 second while aiming. Stacks 10 times. Discharges all stacks upon firing.
MK VI Power Sword will be your horde clear, armor, and boss damage
Alternatively, you could also use melee you can use MK3 for the Perks would be Maniac with either Flak or Carapace. For the Blessings, I would get Power Cycler and Sunder
Another Alternative is Chain Sword. Perks would be Flak/Unyielding. For the blessings it would be Blood Letter and Rampage
You will mostly be in the backline sniping units. With the blessing Deadly Accurate and Surgical you will be able to crit and 1-shot most things in the head with the exception of Ogryns and Dreg Ragers.
The biggest weakness this build will have will be bosses. Depending on the boss it can be difficult to solo it.