Peak Stim Supply
 Hive Scum Build - Warhammer 40k: Darktide 

Build Design & Reasoning

This talent and weapon setup was made to accomplish 2 things: be a solid support for gas-filled Havoc missions while also having strong damage and crowd control. I chose the Chirurgeon's Mk IV Bone Saw because while I preferred the Enginseer's Mk VI Crowbar everywhere else, I want to use this weapon sometimes. Branx MKII Needle Pistol is brought primarily to prep enemies with toxin to ensure they give the most stimm regen. It is also the best movement stick vs ranged walls in the game as well as a good way to regen your Stimm Supply  if out of grenades. 

Stimm Labb

I chose this particular setup to maximize usefulness to both me and the party. CDR is strong, but the keystones are either only useful to some teammates or not impactful enough to justify the cost. This distribution brings +5% Crit attached to +16% Power, +80% Toughness Regen, 16% reduced damage taken, +16% attack speed, +50% swap speed,  AND -50% stamina cost. Well worth losing a bit of CDR/Strength/Crit for that amount of utility. Tip: your stimm regens far faster than your ability ever will because of Sample Collector + Practiced Deployment so CDR is basically useless on this build.

Weapon Alternatives

Honestly, I've ran this build with most weapons and it will absolutely work with anything. Stimm Supply and the toxin stacking the class does will carry you through pretty much any problem so long as your fundamentals are strong. Take anything, you'll still kick ass.

Talent Alternatives

The only talents I would call vitally important to this build is Sample Collector, Practiced Deployment, Fast Acting Stimms, and Chem Enhanced. I used to take Chem Grenade, but have recently fallen in love with the Blackout + Pocket Toxin combo. It allows another class to get more grenade drops since you can regen these while also providing strong CC for packs of Rotten Armour and applying 3 stacks of toxin. If you find yourself not really being able to use Stimm Supply on demand (it does take effort to make sure you're killing things with toxin applied), switching to the chem nade and swapping Pocket Toxin with Extra Pouches will help substantially. Also a good move if the rest of your team has nade regen/doesn't use them.  Everything else just empowers my personal playstyle for the class.