DoT Specialist: Every DoT / Crit / Debuffs / Boss-killer
 Skitarii Build - Warhammer 40k: Darktide 

Overview

This build takes almost everything that increases DoT damage, which can get up to 6k DPS from just Burn and double Bleed. In an ideal testing situation, it can kill an Auric plague ogryn in under 10 sec with one Chordclaw charge and 5 bullets, and a Havoc 40 plague ogryn in under 15 sec with a second charge.

Although the boss damage is great, the build doesn't sacrifice anything for it. It's a solid all-rounder that can handle any situation. It's a high crit melee-focused build, with very fast attacks, which quickly stun-lock enemies with Electro-Strike Conduit, shred armor with System Shock, and stack bleed. Along with the DoTs and debuffs, the Branx Mk XI Phosphor Blast Pistol is perfect for quick swapping to take out specialists and ranged enemies from hip fire. Chordclaw can deal with groups of tankier enemies, and the Purgator Servo-skull can handle tough hordes. The build is also tanky, and has some decent team utility.

Running through an "optimal" monstrosity fight explains how the build works:

1. Double tag to attack with the Artificer Servo-Skull. This will apply a multiplicative 15% damage buff, and start stacking burn.
2. Shoot until 15 burn stacks. This will also add an extra 15% brittleness, and trigger Weakness Analysis Doctrine. (I'm not sure if this is a bug, but the servo-skull will maintain 15 stacks, despite capping at 8 stacks normally.)
3. Use Probing Strikes, which will cap the special bleed stacks, and trigger Moebian Conductor. Since each hit is a guaranteed crit, this will trigger Electro-Strike Conduit, and apply another 30% brittleness from System Shock. After the first hit, Retribution Conduit will be triggered. This also adds 3 stacks of Sustained Assault Doctrine and Uncapped Arrestor.
4. Swap to melee and light attack to quickly cap out buffs, regular bleed stacks, and the max of 55% brittleness. Use a push attack every 4 seconds at least to ensure Channelled Motive Force is up. Chained weakspot hits add Executor stacks, which is also a huge buff to DoTs.
5. All damage talents, DoTs, and debuffs will be maxed for 10 seconds with sustained melee attacks. This is enough to kill an Auric plague ogryn, and in H40 another Chordclaw will keep up the damage. 

A big advantage to the focus on DoTs is that you don't need to play optimally like this - as long as the key DoTs and buffs are up, you can quickly put up enough damage to kill it even if it charges away. In this example, DoTs account for half of the total boss damage (see the preview image for the breakdown).

The build is also particularly strong against Captains, since the Chordclaw bleed will do long-lasting direct damage that bypasses the shield, and burn does great damage against the shield. (Both need to be applied when the shield is down, but the servo-skull can build and maintain stacks when the shield is up).

This is all you really need to know for the build, but I overdid it with theorycrafting, so there's overly detailed reasoning behind the choices below.

Chordclaw

I think this kind of DoT build is the best use of Probing Strikes. With the guaranteed crit, one ability use triggers most of the damage and debuff talents we have up to 3 times, and the DoT damage is significantly buffed.

Probing Strikes doesn't work well with Slice and Dice, since the buff does not affect bleed. So using it repeatedly wastes the DoT, which can do more damage than the initial attack. Similarly, the extra charges from Redline Capacitors also encourage spamming, which works better with Axial Slash.

I don't think Satiated Steel is worth it, since it doesn't trigger if it's the bleed that kills. If I had another talent point, I think Flux Conduit Build-Up is much better for capacitance generation.

Melee

Flesh Tearer is a core part of the build, and Unyielding and Flak damage are important since these perks also affect DoT damage while the knife is out. Unlike melee and range, DoT damage does not depend where the enemy is hit, only on its "Base Armor Type": All monstrosities are Unyielding, and Captains/Twins are Flak.

The much more arguable part is the Executor blessing. I'm normally not a fan of this due to inconsistency, and Riposte is a more obvious choice for such a crit-focused build. However, it works well here for a few reasons: Executor stacks also affect DoTs, and can be a huge multiplicative buff. The build is focused on light attacks with +24.5% attack speed, which helps build stacks quickly. And base crit is already at 40.5% without Riposte. More crit is great for damage and stacking bleed and brittleness a bit faster, but there's some diminishing returns.

This mainly comes down to how often you're hitting weakspots. Not just for the Executor stacks, but a weakspot crit is a much smaller damage increase compared to a non-weakspot crit. I roughly worked it out to: If you can average 2 Executor stacks for the same amount of time Riposte would be up, Executor is significantly better damage.

Either is fine, but Executor is a bit more of an interesting choice, and definitely fits the DoT theme of the build better.

Ranged

The problem with Infernus is that it's great against bosses, but worse at everything else. The damage of 5 burn is very low: Even on crits, and waiting for burn to finish, Opening Salvo does almost as much damage. And most enemies will be be dead before getting two crits. However, the advantage of Infernus on the Phosphor gun is that max stacks are 15, rather than 12 for Lasguns. This is a huge difference: 15 stacks is more than a 40% DPS increase from 12. In the example boss fight above, burn did 22% of the total damage. 

If you want to sacrifice boss damage, a couple alternatives:

• Surgical + Man-Stopper is best for targeting specials/range through hordes.
• Opening Salvo + Crucian Roulette is better for hip firing and quickly swapping back. (You only need to wait very briefly between shots for Opening Salvo to consistently apply)

Although Surgical would apply burn consistently, I'd rather not ADS for long enough to max stacks, and prefer hip firing at the cost of more bullets.

Health Curios with Ablative Wards

I took this idea from this build: https://darktide.gameslantern.com/builds/a222cdcf-8cf0-485f-9619-617e0e5962f4/noospheric-command-tank . I think this is a great idea that works well.

Briefly, the idea is that Ablative Wards can mitigate the more dangerous enemies in higher difficulties, like bursters and bombers. The health trivializes the corruption damage from the talent, and generally adds a lot of protection. Skitarii is great at quickly generating toughness, and as long as we can get back to 100% fast enough, the lower toughness isn't a problem. Chordclaw can be used as a panic button after taking damage due to Voltaic Restoration.

More details and breakpoints are in the linked build, but I'll add one thing. Resurgence with 3x Toughness Regeneration Speed is a significant increase of toughness regen/sec. But there is also a more subtle advantage with low toughness: Unlike most sources of toughness replenishment which are percentage based, coherency toughness regeneration is a flat number per sec, meaning that lower toughness increases the % gained. Without any added toughness from curios (125 total), Resurgence (near enemies) works out to +5.7% toughness/sec. Maxed out toughness (3 x 17% + 3 x 5% -> 208 total) works out to be just +3.4% toughness/sec.

This gets more complicated in Havoc due to hidden modifiers. If I understand kuli's guide correctly, without coherency regen from curios, Resurgence is worse in H40, but with the regen, it might be slightly better.

More Damage Talents?

The only damage talent that affects DoTs we aren't taking is Galvanic Marking Array. The main problem with this is that it doesn't trigger on DoT kills, so it's bad with Infernus. It might be alright without Infernus (or using a different gun), especially if you wanted a more range focused build. However, the damage is less valuable than it seems: Due to diminishing returns on damage, this only ends up increasing total damage by about 10% at max stacks.

We can also get more damage by switching Flensing Protocols to Redline Capacitors due to Advanced Power Management. At max stacks, there is also more damage from Retribution Conduit, though these buffs are much less consistent. However, I'd much prefer to have Servo-Sinew Surge for the crit and speed, making stacking bleed and brittleness much faster. I also don't find myself running out of ability charges very often.

If you're interested though, with both of these together, the absolute max damage possible (nearly impossible to get normally) would increase the overall DPS by ~30%. This would be a bit under 8k DPS in just DoTs, which is pretty crazy, though also pretty pointless.

Better Alternative Talents

Most talents are very important, but there's a few options to drop:

• Dropping Ablative Wards and switching to more standard curios would be fine.
• Purgator Servo-Skull can be dropped, but I think it's definitely worth keeping.
• We could drop a damage node or two. The first I'd drop is definitely Retribution Conduit, since it's inconsistent on this build. It requires a crit on the specific enemy before it kicks in, and is useless for range damage. Also, you should rarely have max charges for better uptime on Sequenced Charge and Moebian Conductor.

Some good options to consider:

• Flux Conduit Build-Up would lower the ability charge time pretty significantly.
• For more defense, Entropic Transfer is an extra 3% toughness/sec with extremely good uptime. Data Sensor Protocol is a huge burst of toughness when you need it most, and gives some team utility.
• As mentioned, you could pivot to a slightly more ranged focus build, with different gun blessings or a different (ideally high crit damage) gun. You'd drop Retribution Conduit and probably Ablative Wards, and take Threat Detection Imperative and Galvanic Marking Array, then maybe Superior Defence Engrams or Ammo-Cell Augury. This loses a benefit of the melee-focused build though, which is low ammo usage.

Damage Formula

This is definitely not important, but since I went through the trouble of estimating the max DoT DPS (out of curiosity I guess?), I figure copying the details might be useful to help understand how damage is calculated. The details of how this works can be found in kuli's Steam guides.

Part of the reason for the high damage is the different multiplicative sources of damage:

• First is regular damage. Adding up all the damage talents: 0.2 + 0.1 + 0.15 + 0.15 + 0.2 + 0.15 = 0.95, or 95% damage increase.
• The Servo-skull gives a multiplicative 15% damage buff.
• Strength is also multiplicative. At max: 0.125 + 0.3 = 0.425, a 42.5% increase.
• The damage increase on a weapon's perk is multiplicative. So a 25% increase against Unyielding and Flak with the knife out.
• Brittleness can add multiplicative damage as well. The main benefit is reducing the harsh armor debuffs, but if brittleness/rending gets past an Armor Damage Modifiers (ADM) of 1 for the armor type, the extra gets converted to damage after being divided by 4. E.g. Burn has an ADM of > 1 for Unyielding, so all 55% brittleness gets converted to damage: 55/4 = 13.75% increase. Bleed has an ADM of 0.75 for Unyielding, so 25% is used to get to 1, and the extra damage is (55-25)/4 = 7.5% increase.
• Burn actually does extra damage against Unyielding, since it has an ADM of 1.5. This seems to be an extra 50% increase on top of the brittleness increase.

Then there's the base DPS of each DoT, which is the base damage at max stacks divided by the tick rate:

• Bleed (normal): 175 / 0.5 = 350 DPS
• Bleed (chordclaw): 175 / 0.375 = 467 DPS
• Burn: 190 / 0.5 = 380 DPS
• Phosphor: 20 / 0.55 = 36 DPS
• (There's technically electrocute damage, but it's even less relevant than Phosphor)

Putting it together as damage against Unyielding:

• Burn and phosphor have at least 1 ADM: 1.95 * 1.15 * 1.425 * 1.25 * 1.1375 = 4.54x
  • Burn also has the 50% bonus, so we can start with 380 * 1.5 = 570 DPS
  • So Burn + Phosphor after bonuses ends up being: (570 + 36) * 4.54 = 2751 DPS
• The bleeds have 0.75 ADM: 1.95 * 1.15 * 1.425 * 1.25 * 1.075 = 4.29x
  • So the bleeds are: (350 + 467) * 4.29 = 3504
• Which totals (2751 + 3504) = 6,255 DPS. This seems consistent with my testing in game.