Veteran: One Shot, One Crusher
 Veteran Build - Warhammer 40k: Darktide 

You have one purpose: one-shotting Crushers. We are sacrificing everything else to serve this one purpose. Why? Because it's fucking hilarious. 

================ The Juicy Bit ================

This setup starts out with two-shotting Crushers with headshots. We get into this range by having a well-rolled Lucius Mk III Helbore Lasgun (with the Carapace Damage perk) and taking Precision Strikes, Superiority Complex, Rending Strikes, and Bring it Down!

The magic happens upon activating Executioner's Stance (Exe) and scoring a critical hit headshot on a Crusher tagged with 5 stacks of Focus Fire! Using Exe will activate Marksman and For the Emperor! to give us the damage boost needed to push crit headshots into the one-shot territory. Because we need the crit to not let our memes be dreams, we take the Deadshot talent and use Surgical on our lasgun. If you have the time, you can aim to build up Surgical stacks and activate Exe just before taking the shot.

================ Weapons ================

================ Ranged ================ 

In terms of stats, you're looking for as much Damage and Stopping Power as possible, preferably >70. Having a high Charge Rate stat on your Helbore will let you make the most out of the 5 seconds of Exe bonuses, especially since the Mk III has the slowest charge rate of the Helbores.

As mentioned in the juicy bit, you need the Carapace Damage perk. If possible, you can also take Unyielding Damage as your other perk to melt monstrosities. 

For the blessing besides Surgical, you can either take Weight of Fire or Sustained Fire. I like WoF for its ease of use, but SF lets you build up more Surgical stacks before firing. Do note that making the most of SF means you'll have to pause after each salvo.

================ Melee ================ 

You can take whichever melee you want as long as it can control hordes. I prefer the Catachan Mk IV Devil's Claw. It has insane trash clear but struggles against Dreg Bruisers with their flak-armoured helmets, though I find that it can stagger them enough. I put Savage Sweep as the second blessing, though Wrath works as well. 

Despite their insane killing potential, I dislike using Power Swords here since you're already a slow, fat fuck. The Mk IV Chainsword, Standard Issue Shovel, and Mk VII Shovel are my preferred alternatives, but once again, use what you're comfortable with. Oh, and if you make a Krieg shovel joke I'll slam your balls in a waffle iron. 

================ Blitz ================ 

Shredder Frag Grenades are great. They'll stagger enemies and give you space when getting overwhelmed, and two of them will kill everything besides ogryns. Krak Grenades are good for dealing with Bulwarks but are redundant for Crushers and Monstrosities. Smokes are too expensive point-wise.

================ How to Play ================

================ Stamina ================

Since we're using Deadshot with Exe and the Helbore's hipfire is like pissing with morning wood, we take at least 2 3-Stamina curios. You can take 3 if you're not a bitch. We're also taking the Target Down! node of the Focus Target! keystone. This will return stamina whenever a tagged enemy dies, and you should be tagging a lot. You don't need to wait for 5 stacks every time; I value dealing with targets faster more than 5-10% extra stamina back. Some people like to take Duck and Dive, but I can never activate it consistently enough to feel good.

================ Melee and Hordes ================

You'll be using your melee a lot and will probably have it equipped when roaming around. However, the Helbore's sluggish equip time makes dealing with sudden elites harder. You could activate Exe, but that could leave you without it in case Crushers show up and you won't be able to do the funny. However, remember that you have Tactical Awareness so don't feel as shy if you hear specialist spawns. Since I like doing the funny, I'll play suboptimally and slowly walk around with my lasgun out in case a Crusher shows up.

The Mk III Helbore's bayonet is hot ass but not unusable; it has a fraction of the speed of the Mks I and II bayonets with basically the same damage. It's good enough to deal with meandering trash and can one-shot Poxhounds, and it lets you deal with random trash while keeping Exe up. However, you need to swap to melee when there's more than 5 enemies coming at you. 

When elites spawn during hordes, pray that your team can manage the horde while you dodge back and shoot. The horde will keep coming, so you dodge on sound cue while maintaining fire. The Helbore's low mobility makes this hard, but it's doable with practice. I've danced in High Intensity Damnation hordes for long enough to kill most of a Gunner squad before needing to refocus on clearing trash. I like charging during the dodge and shooting as it ends.

Don't forget that a charged up Helbore shot has cleave, so fire away even when the elites you marked are behind trash (you are marking them right?). Beware, it can take a few shots if the horde is too dense. Additionally, you can hide behind your local Ogryn and shoot through him. He'll be fine; it just tickles him.

================ Sustain ================

In terms of ammo, having Survivalist and Shock Trooper with a high crit rate gun makes you incredibly sustainable. You can leave most of the ammo for your team. Shock Trooper also makes your magazine last longer, so I don't find reload talents necessary.

This build is too greedy to afford grenade regeneration talents. I usually save my frags to cover a revive or to drop two when 20 Ragers show up.

================ Flex Talents ================ 

• Redirect Fire: When you still have the Exe bonuses up, a crit headshot will almost one-shot a Scab Mauler depending on your damage rolls and falloff. The buff from Redirect Fire helps you meet that breakpoint more consistently when they're up close. You can swap this for Longshot if you want to go further into that subtree; it doesn't help when the Maulers are at kissing distance but doesn't require a prior kill to activate.
• Shock Trooper: Since we have Survivalist, you're going to be almost ammo positive through missions. This may be overkill if you consistently play in teams that don't use much ammo, such as having friends who mainly play staff psyker.

With your extra points, you could

• Take 5% Melee Damage Boost. The melee boost lets you one-shot shooter trash (Stalkers) in the event you're forced to use the bayonet. I couldn't reach that breakpoint with an 80 damage and 80 stopping power Helbore, and this is more consistent than relying on the buff from Redirect Fire.
  • Reciprocity helps keep your crit rate high when you're shooting quickly (building up less Surgical stacks) and when you're out of stamina (no Deadshot bonus). It will also help out your melee.
  • Duck and Dive is another source of stamina regeneration. I personally haven't been able to activate it often enough to feel good, but I've heard people swear by it.
• Swap The Bigger They Are... for Counter-fire to help deal with Stalkers. Synergises with Catch a Breath since you can regenerate toughness while picking them off.
• Take Stamina Regeneration Boost to help with Deadshot and melee pushing. 
• Take Demolition Team for grenade regeneration.

You could also swap Focus Target for Marksman's Focus to still hit the one-shot Crusher breakpoint, but have fun playing with that.

Scabs are getting worried, they've all gone underground.

When One Shot Harken sees them, they'll know they're going down.

And next time when see the Scabs with their faces full of fright,

remember One Shot Harken and his friend named Eamon Wright!