6.5-8% Strength for 3.5s on Hit. Stacks 5 times.
Hitting at least 3 enemies with an attack, increases your damage by 24-36% for 3 seconds.
Target receives 1-4 Stacks of 2.5% Brittleness on direct projectile hit. Debuff lasts for 5 seconds and can have a maximum of 16 stacks.
3.5-5% Critical Chance for every 10% of magazine spent during continuous fire. Stacks 5 times.
Stealthy zealot, packing armor/boss damage in Boltgun, Blades of Faith for ranged specials, and melee for everything else.
Ranged: Boltgun damage against boss can spike up quite high with stacking the following: 25% unyielding from perk, 25% in close range (Anoint in Blood), 20% from behind (Ambuscade), 20% from momentum stacks, +20% unyielding (Purge the unclean). While also stacking up crit chance from Cavalcade blessing, and more importantly - from Shroudfield grace period (roughly first second of invisibility) where you have bonuses from Shroudfield, but it doesn't interrupt invisibility yet. You can shoot roughly 3 bolts with 100% crit chance, if you use it while shooting.
Ideal scenario of "how to burst boss" is: run around for 20 momentum stacks, run behind the boss, start shooting, press F roughly after first shot. Basically, only use Boltgun vs big chunks of elites and bosses.
For specials - mostly rely on melee and Blades of Faith, because taking out Boltgun takes some precious time.
Melee: Any crit-oriented melee can work with it, Devil's Claw is nice alternative that has better mobility and some fun gameplay with parrying, or good ol' knife. Melee gameplay is roughly same as other crit oriented builts, BUT, we can utilize Shroudfield grace period as well. If you use it while doing heavy attack, you'll perform one empowered attack and keep invisibility for another strike.
It's quite squishy build, while mobility should keep you away from most melee threats, every elite gunner can kill you quite quick if you aren't careful, respect them when dealing with big room filled with them, break LoS, keep dodging, and retreat when required.
Always prioritize doing objectives, Shroudfield helps with everything, hacking, carrying power cells, scanning, etc.
Picking Loner is mostly required to get all necessary perks, but it helps with clutching, scouting for resources and doing objectives solo.
As for question: "why not play stealthy hammer instead?" - it's just different approach, pivoting boss and elite damage to Boltgun, while making you free to pick some fast and reliable melee instead, more capable of clutching games.