Devil's Claw Scum
 Hive Scum Build - Warhammer 40k: Darktide 

Devil's Claw works really well on Hive Scum. The class has lots of relevant bonuses for the weapon while also being able to counteract its weakness to carapace armor through the needle pistol (and optionally Boom Bringer). While the Devil's Claw will typically have lower DPS than a comparable shivs build, it has way better cleave and the parry special attack is very powerful defensively. It's also a lot of fun to use.

You can dump either Mobility or Cleave Targets on the sword. You gain 1.0 cleave mass on heavies and 0.6 on light attacks going from 60% to 80% Cleave Targets, whereas going 80% Mobility significantly increases your movement speed; I prefer maxed Mobility. I take Skullcrusher instead of Rampage blessing because the build has power bonuses from Rampage! ability and cartel stimm, as well as 2 stagger pulses from Forge's Bellow per ability cooldown, so it's decent at staggering most enemies and Skullcrusher is a much larger damage bonus when it's active. Forge's Bellow even staggers monstrosities, so it's great to stack up Skullcrusher for a quick beatdown.

Needle pistol is the answer for crushers and anything you need to kill from range. It's also good for preloading toxin stacks before going into melee with bosses/monstrosities. Since the build is melee-oriented, you will be able to easily maintain ammo with Pickpocket.

Pickpocket is more or less required on Havoc, but is optional on Auric and below if you're conservative with your ammo. If you skip Pickpocket, that point can go to Sample Collector (which also gives the option of taking Ruffian aura), Street Tough, Adrenaline Unbound, Stoked Rage, or whatever you want.

Adrenaline Smiter can be swapped for Stoked Rage if you want. They give similar uptime on Adrenaline Frenzy. Smiter has shorter ramp time in most situations, but you may lose the buff when soloing bosses/monstrosities or when your teammates are getting a lot of the kills.

Blitz can be whatever you prefer, but I've come to favor Blackout because it has great utility, helps activate the Skullcrusher blessing,  and feels less cheesy than the other options. Boom Bringer is the overall strongest and is a good choice if you want the best chance of success in worst-case scenarios.

Channelled Aggression is tempting, but Catachan Mk VII "Devil's Claw" Sword relies more on light attacks than heavies for single-target DPS. Parry also counts as a heavy attack, but the rending is mostly important against crushers and you're probably not waiting around to perfect-parry crushers very often during Rampage. If you were to use Catachan Mk IV "Devil's Claw" Sword instead, then I would recommend swapping a point from somewhere to take Channelled Aggression, and possibly the +15% rending path on the cartel stimm also.

You can swap one or both of the +3 stamina curios for toughness or health if you want more defense. Stamina scales your attack speed through Swift Endurance, your maximum potential parries before block break, and how much stamina you get back from Regained Posture. Block efficiency perks can be replaced with health, especially for Havoc.

In the stimm lab, all of the strength capstones are good. +35% finesse gives about +18% overall damage on the Devil's Claw assuming you consistently hit heads and have ~40% average crit chance. +15% crit chance gives about +11% overall damage, but it has added value from proccing Hyper-Critical more often and has synergy with Precision Violence and Adrenaline Frenzy. Rending is probably the weakest path since chem toxin has high baseline armor penetration already, and 15% rending isn't going to be enough to make the Devil's Claw strong against crushers. I went with increased crit chance for the talent synergies.

I like the Mk VII Devil's Claw best, but you can use a different variant if you prefer. I've included suggested attack combos below for each variant of the weapon. There's quite a bit of room for improvisation with the attack combos, especially when mixing in parries and push attacks.

Catachan Mk VII "Devil's Claw" Sword

Horde clear: heavy > light > repeat OR heavy > parry/block cancel > repeat

Single target: light > heavy, then (light x2 > heavy > repeat) OR push attack > light x2 > heavy > repeat
OR spam light attacks

Monstrosity/boss aggro: parry when possible, then spam light attacks between enemy attacks

Catachan Mk IV "Devil's Claw" Sword

Horde clear: light > heavy > repeat OR spam light attacks

Single target: heavy > light > repeat OR heavy > parry/block cancel > repeat

Monstrosity/boss aggro: parry when possible, then use the single-target combo between enemy attacks

Catachan Mk I "Devil's Claw" Sword

Horde clear: spam heavy attacks

Single target: spam light attacks

Monstrosity/boss aggro: parry when possible, then spam light attacks between enemy attacks