Terminus Warrant viable
 Arbites Build - Warhammer 40k: Darktide 

The idea is to use increased AS from terminus stacks with other bonuses to quickly deal with elites in close range - mauler/crusher, and having a backup ranged weapon to quickly deal with trapper/flamethrower/back off from maniacs. 
Flex points - You can forgo toughness restoration from "Terminal Decree", or give up extra melee increase on your push attack - light combo by swapping "Strike Down", in favor of Rebreather/Monstrosity hunter or whatever you want. Same for Ammo belt, but ammo is needed on that build more then ever.
Weapon alternatives:
Melee - Chainsword (doesn't lose stacks too much, good damage)/Arbites shock maul (not great with stacks, but good weapon)/Classic shock maul (skullcrusher is good to have)
Ranged - Infantry autogun (better all-rounder, bit worse mobility/specialst)/Vigilant autogun (good with finesse bonus at 30 stacks for huge crits, but you suffer from supression)/Arbites shotgun (losing all stacks on single cleave doesn't feel great, but its good to get melee stacks if you want to play like that).
Grenade - I use arbites nades because it allows me to easily proc skull crusher on bosses or in general just stun bosses in bad position often. Ofc shock mine is good and may be preferable.
Dog - You can go dog on this build, but it doesn't add that much to terminus warrant idea, so rather run lone wolf