Anti Armour Scummer
 Hive Scum Build - Warhammer 40k: Darktide 

Use neuro toxin on the banana blade to proc 2% recharge on stimm from Sample Collector. This should lead to stimm being up within 25 seconds or less after uptime ends.

Long Lasting would be nice to have, but it has anti-synergy with Dependency, since your Dependency stacks begin decaying while the stimm is active, even though you can't use Sample Collector to replinish it during active use.

Our goal is to keep crit chance as high as possible to maximize the potential of Hyper-Critical. For this reason, we take +15% Crit Chance on our unique Stimm to ensure that we can quickly dispatch Maulers and armoured Ragers efficiently.

The Sweet Spot substantially increases the damage of this build, as well as permitting safe one-shots with the Bone Saw's heavy-1 attack against Auric Maulers. It's also possible to one-shot all shotgunners and gunners with a single light-1 attack if Decimator is high enough (around 5+ stacks).

Boiling Blood seems necessary for this build to function. While I don't like the prerequisites for Channeled Aggression, it does substantially increase our damage against carapace armour without the need to swap our toxin from neuro to brittleness mode.

Coated Weaponry is actually somewhat attractive since we'll have nearly an 85% crit chance at nearly all times with this build. It would permit us to apply a single stack of neuro toxin while keeping our Saw in brittleness mode at all times, allowing us to frequently proc the 2% bonus recharge rate from Sample Collector. Unfortunately, I don't think it's possible to acquire without sacrificing a meaningful damage mode, and the possibility of chains of bad luck could severely screw us out of precious uptime on our stimm.

Hyper-Violence doesn't seem to give this build a substantial damage increase. With Hyper-Violence, my top DPS in the Psykhanium was about 2.3k. Once I swapped from Hyper-Violence to The Sweet Spot, I was able to reliably hit 2.1k at all times, and occassionally spiked as high as 3.3k against Mauler and Crusher packs.

For more reliable cleave, it might be worth it to swap Decimator with Shock & Awe. The only real difference I could discern between this exchange is slightly slower boss kill times, and the inability to reliably one-shot flak-armoured Gunners and Shotgunners.