Nuncio High Stand ( Havoc 40 )
 Arbites Build - Warhammer 40k: Darktide 

Build alternatives :

1. Even so the Indignatus Mk IVe Crusher doesn't have other marks to try out, you have a few blessings that you can use. Slaughterer for better damage scaling against any kind of non carapace armored enemies, Opportunist if your team already have a lot of britleness or simply because you desire more immediate effectiveness. Skullcrusher being an absolute necessity for this weapon, the blessing you might swap will be Thunderous, but keep in mind that this will be the highest potential damage against the widest potential enemies. ( Thrust make this weapon slower to use, and at higher difficulty, simply won't allow you to maximise your damage output. )
2. Both Godwyn-Branx Mk IV Bolt Pistol are usable. The Mk IV having better damage and guaranteing killing gunner elites with 2 shots + 8 stacks of bleed ( Puncture ) and better damage output against Scab Rager. Meanwhile the Mk VI having better stagger ability, but that isn't needed much due to Concussive and Forceful. Maniac damage can be swaped out for Unyielding damage to boost your bleed damage against monstrosities ( cause yes, that is how it works ).
3. If, for any reason, you aren't one to like the Godwyn-Branx Mk IV Bolt Pistol, you can exchange it for a Judgement Mk IV Subductor Shotpistol and Riot Shield, or Exaction Mk III Exterminator Shotgun for similar use and efficiency.
4. No Escape and Hammer of Judgement are about the same value. Hammer of Judgement bring you better dps ( this weapon being very reliant on it's attack speed ) on proc ( which the higher you go in difficulty, the more you'll have it up ), while No Escape bring you mouvement speed which can never be bad and fit the theme of this build better. 
5. Speaking of the theme of this build, you are basically playing a heavy stagger / horde control / rescuer build. which is why True Grit ( allowing you to soak more hits when you revive ), Nuncio-Aquila ( being worse for dps than Break the Line but a much stronger support / rescuer option ) and Fear of Justice ( allowing you to be hit less as you revive ) are there. BUT, without completly breaking the theme of this build, you could remove True Grit and Fear of Justice for Zealous Dedication + Prosecution Blow to give yourself a significant boost of damage overall or Arbites Vigilant + Judicial Force to still boost your damage but stay closer to a support idea. Your call !

Strength :

• You are an extremely strong tanky support. Voltaic Shock Mine paired with Lone Wolf allowing you to give crowd control on demands troughout the game. Forceful + The Emperor's Fist + Impact Boost allowing you to stagger everything but monstrosities ( yes you can stagger captains as well ). Nuncio-Aquila + Inspiring Recitation giving your team exellent standing power and survivability on a 32s basis ( it last 20s, the cooldown start immediatly and it's on a base 52s cooldown after ability cooldown reduction from curios )
• You empower reviving speed to the maximum. You yourself acumulate 30% revive speed from curios and 30% revive speed from Inspiring Recitation on Nuncio-Aquila activation. Fear of Justice will diminish the risks of any save scenarios. Best case scenario ? Having a Zealot with Shroudfield, 30% revive speed from its curios + Providence reviving a down teammate while standing in your buffed Nuncio-Aquila. IN any case, you'll be able to revive your team at terrifying speed. Also, Forceful fully stacked melee attacks + Voltaic Shock Mine + True Grit will allow you to revive in otherwise unsavable scenario. 
• Using different tools, but you create as much space as an typical Loyal Protector Ogryn due to the Raw stagger that you possess in addition to Voltaic Shock Mine and Nuncio-Aquila. ( are you starting to see a patern there ? ahaha )
• Up Close, Force of Will, Walk It Off, Toughness Damage Reduction, Arbitrator Armour, Suppression Protocols, Plasteel Plates, Lone Wolf, Nuncio-Aquila + Inspiring Recitation, Hold the Line and Forceful + Will of the Lex will maintain you at a very high toughness level at all times. Meanwhile True Grit while assure you secondary chances even against the heaviest hits ( Crusher overheads included ! ).
• Not only can you hold Scab Captain ( twins included ) and Monstrosities basically forever, but you will also inflict consistently high damage to Scab Captain, hitting them for 10k not being a rare occurence. Monstrosities are more resilient to your damage type than Scab Captain but given enough time and hitting weakspot consistently, you will also be able to handle them. ( Time being one of the thing you can have and create almost at will.
• Your Indignatus Mk IVe Crusher blessing combination allow you to not only stack 16 stacks or 40% britelness on any target you hit twice ( Thunderous ) but also allow you to generate 8 stacks of Skullcrusher in the same 2 hits with Concussive, basically allowing you to stagger and damage even the toughest Rotten armor enemies. This combined with Nuncio-Aquila and Voltaic Shock Mine giving you immense ammount of time will make Carapace armour spam much easier to deal with. 
• Nuncio-Aquila actively empower the gun play of your entire team, by giving them Supression immunity, 30% suppreasion dealt, 25% recoil reduction + 30% toughness damage reduction from Inspiring Recitation. Even non Veteran class can outgun gunner spam.

Weakness :

• The Arbites is a class that is use to play majorly for itself. Sure, Havoc 40 games require grouping to begin with, but all apparent and meta tools are almost completely independent of of your teams presence. This build is the exact opposite of this idea. You are here for your team and with your team ( trough the form of revival speed and Nuncio-Aquila buffs ), not simply as a tool that had add to an already formed cohesive group. This fact can make it difficult for people use to an indepedant playstyle that use strong individual tools. ( keep in mind that this doesn't make you a slouch on your own, simply do not expect to be able to play on your own as you would generally )
• Yes, you create space. Yes, you can stagger almost everything in existence. Yes, you can damage and kill everything. Yes you can all of this, but as this build is mainly supposed to be supportive, you are slow at it. If you ever find yourself alone, you have better chance trying to save your teammates than handling infinite hordes and boss spawns. ( No Break the Line, no Castigator's Stance and no meta fast weapons that you would typically see like the Branx Mk III Arbites Shock Maul )
•  You aren't using a dog, diminishing your ammo evonomy and your ability to safely eliminate specialist or entranched gunners. 

Special Info :

The Indignatus Mk IVe Crusher is a slow weapon that can deal a significant ammount of damage if understood properly.

• Your Special attack is basically completely useless. Unlike the Achlys Mk I Power Maul, a similar weapon that possess a nuke on a 10s cooldown, you won't even be able to one shot a normal flack enemy on use with it. Yes you can spam it infinitly but be it in term of damage or stagger, everything can be done and is better without using it at all. That is why the dump stat of this weapon is Power Output. ( This can change based of patch changes, so be aware of when you are reading this build )
• The combo against any single target is heavy into light into heavy ( repeat as many times as needed ). You do not need to fully charge the heavy if you aren't using Thrust. 
• The combo for horde clear is push attack into heavy. ( repeat as many times as needed ). You will have amazing stagger from the push attack followed by a lateral cleave. Of course it cost Stamina to do so, but this can be sustainable by getting 80% defense, Rapid Movement and careful managment of your stamina troughout the game. 

Another info that you can pay attention to for this build. This Godwyn-Branx Mk IV Bolt Pistol can kill some enemies in headshot ( like a Scab Trapper ), but generally speaking, it'll kill anything in 2 body shots + bleeds. The idea being, if you see gunner elites, don't use 3 bullets, use 2 and let them die. 

All of those info are valid in Havoc 40, making it valid anywhere else. Simply keep in mind that the lower lever you are at, the less the damage calculation being portrayed here matters.

Conclusion :

This build encourage a slower supportive and protective playstyle, you role being similar to a Loyal Protector Ogryn. You aren't here to do immense damage, even if you will still contribute significantly, you main contribution is elsewhere. Giving your team Space, staggering key targets, maintaining toughness high, and when needed reviving your teammates or protecting the ones trying to do so.
Mainly a frontliner, you are still perfectly capable of handling range combat, be it with ammo ( gunning directly ), or without ammo ( letting your team do the gun play while supporting them with Nuncio-Aquila ).

Meta ? of course not ! you're starting to know me by now ! Rare i might even say, considering how little Nuncio-Aquila build you see being used in high havoc. Strong nonetheless, extremely useful and powerful in it's given role. Finally allow you to not have a Ogryn in your team without removing the space it create. A fun, unique and different way to play a characted that basically always use the other 2 Abilities. 

Usable even in Rotten Armour Missions with high success.

I encourage you to try it out and tell me what you think ! ;) ( Giselle5957 on discord ;) )