Target receives 1-4 Stack(s) of +10% Damage if already Staggered. Lasts 5s.
Hitting an enemy gives them 1-4 stacks of 2.5% Brittleness. Debuff lasts for 5 seconds and can have a maximum of 16 stacks.
+10% Critical Chance for every 0.2-0.35 second while aiming. Stacks 10 times. Discharges all stacks upon firing.
+30-42%Melee Strength for 3.5s on Hitting 3+ Enemies with a Ranged Attack.
I went with Gunner damage resistance on all three curios due to the sheer number of Gunners I've been seeing lately, that can be swapped out if FS ever reduce their spawn rate. The third curio perk is entirely up to your personal preference.
The Mk. IIIb is an amazing all-around melee weapon that mulches hordes, stunlocks monstrosities with the slap, and can kill Crushers on Damnation in 2 to 4 heavy headshots.
The Kickback with Expansive enhances your already impressive melee damage, and with Surgical it can even countersnipe Snipers shockingly well. It's also great at interrupting or outright killing Ragers, and knocking down Maulers, Crushers and Bulwarks that are about to pulverize a teammate across the room.
This build really has it all; strong survivability, excellent horde clear, great anti-armor, and the ability to outright bully monstrosities.