Hotshot Secret Agent Auric Maelstrom
 Veteran Build - Warhammer 40k: Darktide 

Build with Auric Maelstrom in mind
 
This is a specific build for an aggressive playstyle that understands melee combat as well as supporting the team, similar to how an Ogryn plays. You need to understand the stagger breakpoints for enemies, the build is meant to react quickly to any danger and halt it, if not kill it immediately.

Build doesn't depend on aura or blitz, so if you prefer different aura or grenade switch as preferred, I prefer never requiring a single ammo pickup and the sheer utility of 6 shredder grenades during enhanced-blitz events. 

STEALTH:
The reason for stealth ability is not to ghost your team when they're relying on you, or to do knife zealot tomfoolery, it is your 'oh-shit' button as well as a key positioning tool for you as the sniper and anti enemy-sniper, as well as Objective completion. When you or an ally call out a sniper sighting, your goal is to run to LOS with the sniper and shoot it before it gets a single shot off. You can do that easily with stealth as the sniper will not fire at you, and your Vraks 3 can quickly lock them down or insta-kill them. The key to playing stealth as a supporting team-member is to play as if you do not have stealth, you clear horde (easily with light attack spam) and push positions with your team. At the beginning of a charge or encounter, you can stealth past the melee enemies to the gunners (often snipers too) pack and turn them into mulch with your handheld lawnmower. This way you can help your team advance without aggroing everything with your attention-grabbing vraks

What if I stealth past enemies to gunners, and there's ANOTHER pack of gunners past them? Even then, if there's another huge pack of gunners beyond your position(only if they have noticed you and are preparing to fire), you can switch to Vraks and open fire at head level sweeping back and forth depending on the amount of gunners and either kill them all or at least suppress them until your team joins you. The decision to open fire or retreat back to team depends on your judgment, but its preferable to always retreat back to team quickly after a stealth mission and initiate encounters as a team. 

The most important aspect of stealth is that even after you break stealth and attack, enemies will not see you or attack you for several seconds. This allows you to pull off your own unique stealth-shenanigans, for example: 

You don't want to aggro a huge pile of armor and then stealth to leave your unaware team to be hit at full-speed, but what you CAN do is: run right up to the maulers' faces, stealth, and then immediately begin spamming light attacks at them. They will not attack you because they're still processing stealth, and they wont prioritize you either because of Low Profile, meaning instead of charging your allies, they will stand in place, held back by a combination of your stagger and your body hitbox and they will die and die. This lets you pull of a pseudo-second-frontline where temporarily you get to melee everything to death, really good for thinning the ranks of armored humans. Bulwarks and crushers are different, you can still kill them with heavies and and shredder attacks but it's protocol to get in coherency with your team and work together to make sure there's no damage and they die quickly. Stealth is also nice for a quick revive in a pinch

STEALTH TRICKS THAT DO NOT GRIEF TEAMMATES:
STEALTH IS INSTANT - PUSH BUTTON - RECEIVE SAFETY - fatshark will probably nerf the instant-cast but for now it is a great power to exploit.
 

- A trapper is firing net at you when you're alone > If you miss dodge, you die, don't take the risk unless required, just stealth, trapper will run towards team, kill it beforehand, problem solved.
 

-FLAMER SHENANIGANS : You and team are fighting back an overwhelming horde that isn't dying fast enough and there are flamers /trappers hidden in the horde >You can do a foolish maneuver I used to do anyway before stealth, run forward in horde drawing aggro of flamers to you so that when they fire they fire away from team, it's important to let them get a small amount of fire out because you're buying time for your team to react, as much as safely possible. The moment you're in real danger, hit stealth to instantly drop all aggro, flamers will start to move and you run at them and kill them asap. This is trickier vs trappers because you can easily just get trapped and die, but even if all you do is offset the rhythm of the trappers intended attack you have succeeded at buying time for team to react. The game often tries to synchronize enemy specialists to all attack at the same time, mutants impact, dog dive, trapper net, flamer fire all tries to fire at the same time, maximizing likeliness of an attack hitting

-Betray the Traitors- There is a pack of armor + specialists charging your team > Unless you're confident that you can shoot the specialists dead before they arrive, run as far as you can towards armor safely, stealth before hit, turn around to face direction of enemy charge, charge with them while swinging at the backs of the specialists. Meet your team in the middle again and jump around and let fly a 'For the Emperor' to let them know you would never abandon them. 

-You are charging enemy gunners, and right as you are about to reach them they open fire > Stealth and save toughness, kill them from the safety of stealth + Low profile. Even though reapers die ultra-fast to vraks do not underestimate what a Green Reaper can do to you if they start firing before you reach them, they can 100-0 you alone and it is very embarrassing considering you killed 6 reapers easily with no damage just moments ago. Darktide. If you do get caught in suppression-hell by a reaper your only hope is to draw your vraks and fire into their face until they die

-Crusher/Mauler swing is going to hit you, you are suppressed/staggered/out of stamina/caught on terrain collision and cannot do side dodge > Stealth, because you were insta-dead anyway

VRAKS mk III Headhunter:
This thing pumps out damage into human targets, reapers, and monstrosities. It's especially fun for killing gunners. The suppression of vraks is weaker than braced autoguns, but not by much, and the raw killing power of the 3-burst shots often means a gun group will be chopped apart, break, panic, and flee just by firing a few bursts at them. A common strategy for a hall of gunners is to simply open fire at full auto at every head I see while walking towards them, if there's no armor in there, you can control the whole encounter yourself. It's only truly outmatched against an extremely wide area of gunners, and even then only because you cannot fire in every direction at once. The sheer amount of control, versatility, and killing power of the Vraks makes it the perfect gun for a stealth veteran. You can snipe maximum range snipers and also hip-fire unload into any face that gets too close. Vraks also easily kills bosses, especially beasts of nurgle provided you're firing into the weakspot. Yet another opportunity for stealth to shine and position yourself to assassinate the beast, but I've solo'd lesser-plague ogryns before they reached the party with the vraks. My vraks has 80% damage and only 70% stopping power, so it doesn't even require perfect breakpoints to be good in every situation. I tried the Columnus V and want to play with it more, but haven't got a good enough roll or the blessings needed to really test it. Even then I would miss the ability to snipe 4 snipers at long-range too much to turn away from vraks.

TL;DR
The build is made to deal large amounts of lethal damage quickly and then switch gears to the next weapon. If you're not sure what your job is:
Find the densest horde and mulch them until a specialist is in view, push block, switch to vraks, dakka dak, back to mulch, and repeat. Alternatively find a door and swing through the wall at the coming enemies. Make sure to do samurai bushido at Mutants ( Rev, wait til mutant charges, side dodge left, swing heavy as they pass, they die) or just left-click them to death like anything else. If your team is pressed by an overwhelming horde of armor and meat, throw every single grenade you have in every direction of dense horde you see until they are dead. You regen grenades fast and need to use them often. Use stealth to kill every single gunner on your screen with Vraks, kill snipers, kill flamers, kill dogs, kill trappers, kill bombers, kill heretics.

I've also run this successfully with the Devils Claw mk IV but I prefer the chainswords' ability to ignore whatever armor type it's versus and swing indiscriminately at heresy of every kind.