High range Gauss build optimized to kill as many enemies as quickly as possible. 170-200 KPM depending on tilesets.
Invert hold/tap abilities for [Gauss] in settings, thank me later. Keep Kinetic Plating and Redline activated at all times. At 100% redline, cast the heat version of Thermal Sunder twice, followed by cold to nuke. Your button presses should look like this: Heat > Heat > Cold. While below 100% redline, alternate between heat sunder and Mach [Rush]. Your button presses should look like this: Heat > Mach [Rush] > Heat > Mach [Rush] > Cold.
For an explanation on why this works, read the rest of the guide :D
The damage of heat sunder scales off the damage of existing heat procs. Since heat sunder itself deals heat damage, it creates a feedback loop that causes the damage of heat sunder to scale exponentially with each subsequent cast. By default the damage is multiplied by 1.5x per cast, but with Redline and [Archon Vitality] buffing sunder, it jumps to 3x per cast. Casting cold will strip enemy armor and deal the remaining damage of all the heat procs in a single hit. Casting two heat followed by one cold is enough to nuke fodder enemies up to level 1000. With some heat inherit shenanigans, you can easily hit damage cap in a few heat casts, the ultimate big funny number nuke.
[Gauss] has two gauges, his battery (the battery gauge at the bottom right), and the Redline counter (the number that appears beside the battery gauge). One of the most common misconceptions about [Gauss] is that his armor strip is based on his Redline counter. This is simply not true. Redline simply gives you the ability to armor strip, but the amount of armor that is stripped scales off your battery level. This misconception stems from the fact that without the use of [Corrosive Projection], it is impossible to full strip enemies in a single cast while under 100% Redline due to the passive battery drain, so people just assume that he can't strip.
Redline gives you buffs, the strength of those buffs, including armor strip, scales off your battery level. Note that armor strip works differently compared to the other buffs. It only scales off the top 20% of the battery. So at 80% battery, you will get 0% strip. At 90% battery you get 50% strip, and so on. The other buffs (fire rate, reload speed, casting speed etc.) scales off the entire battery.
For someone unfamiliar with [Gauss], it might seem weird to see people build him with no strength. But trust me, you don't need it. Thermal Sunder scales exponentially, so it's in a pretty weird spot when it comes to damage. One heat cast will tickle steel path enemies, but two casts turns them into tomato sauce. Whether you're at 100% strength or 300%, you will need at least two heat casts (and one cold) to nuke steel path enemies. Building for strength is completely pointless as you will still need the same amount of casts to nuke. It can be helpful in base star chart, but in steel path It is much more effective to build for duration and range.
Corrosive projection (Important) - By default, you need a full battery to full strip, but because of the constant battery drain, it is impossible to maintain full battery without maxing your redline. No full battery means no full strip, and not being able to full strip completely kills Thermal Sunder's damage. Sure, you can wait for redline to charge. But waiting? Who wants to do that. [Corrosive Projection] reduces enemy armor by 18% that stacks additively with abilities. This means Gauss only needs 96.4% battery to full strip, completely bypassing the wait. But isn't 100 - 18 = 82%? Why is it 96.4% instead of 82%? Because the armor strip scales off the top 20% of his battery (the part that's unlocked when you activate Redline). You need that upper 20% to be 82% full to full strip with [Corrosive Projection], and that is 96.4% of his total battery. By alternating between heat sunder and Mach Rush, you can keep your battery above 96.4% for your nuking runs. You can watch my guide video guide for more details.
Archon Vitality - This mod will triple Thermal Sunder's damage per cast, instead of double. This mod is a huge damage increase, and is the reason why you never want to build above 100% strength. Just two heat casts followed by one cold is enough to nuke fodder enemies up to level 1000. This mod will also improve your energy economy since less casts are required to kill.
Primed continuity - Mandatory duration mod. Stacks with archon shards and molt efficiency to give ~1 minute of kinetic plating and redline.
Range mods - Mandatory range for Thermal Sunder to effectively nuke rooms. In my opinion, anything under 265% range is too small but if you're comfortable with less range or don't have enough duration shards, you can swap out augur reach for Constitution or Augur Message.
Streamline - [Gauss] is an energy black hole, [Streamline] is mandatory for endless Thermal Sunder spam. Best used with [Seismic Bond] on your companion for an additional 30% efficiency. Because of DE logic, Kinetic Plating and Redline counts as a channeled ability and will proc it. If you're still experiencing energy issues you can use fleeting expertise but it will require you to slot in more duration shards.
Rolling Guard - Gives you i-frames for status cleanse and helps with shield gating. [Gauss Prime]'s shield gate lasts 1.83 seconds, if you activate [Rolling Guard] near the end of the shield gate he will almost fully regenerate his shields thanks to his passive. If you're feeling confident, you can replace this with [Constitution] or Auger Message for more duration. For shorter missions where you won't have enough time to stack Molt Augmented, swap this out for Umbral intensify. It won't reach the desired 100% strength, but it helps.
Exilus - Flexible slot, use anything you want. I personally use Cunning drift for endurance runs, and Rush to speedrun through shorter missions.
Molt Augmented - Mandatory for hitting 100% strength for 100% damage resistance on kinetic plating.
Molt Efficiency - If you're following this build mod for mod, Molt Efficiency is mandatory for hitting ~1 minute duration for Kinetic Plating and Redline. If you're building for more duration, this slot is flexible for Arcane Energize or any other arcane you fancy.
Helminth isn't needed in a [Gauss] nuke build. But if you really want to you can infuse roar into Kinetic Plating. Roar acts like a second [Archon Vitality] and increases the scaling multiplier of Thermal Sunder. But why Kinetic Plating? Enemies will be permanently stun locked by the constant sunder spam, making Kinetic Plating the least useful ability in [Gauss]' kit. Alternatively, Norish is good for extra energy generation and will apply viral on enemies that hit you. It also enables meme tanking strats with [Quick Thinking] (Please don't do that).
Thermal Sunder struggles to kill eximus units since it doesn't scale properly on overguard, so your weapon choices will be specialized for slaying eximus. There are two ways you can approach this:
A strong single target weapon to kill eximus units outright. Any strong weapon will do, some examples are the [Felarx], [Furis] Incarnon, [Torid] incarnon. Playstyle would be to nuke a room, and then use your weapon of choice to kill any surviving eximus.
A heat primer to prime eximus units, and then kill them with Thermal Sunder. My recommendations are [Kuva Ogris] or [Epitaph]. [Kuva Ogris] can apply a high damage heat proc to help sunder scale faster. It also does enough damage on its own to finish off any eximus units that didn't die to sunder. [Nightwatch Napalm] will continue to prime enemies. [Epitaph] is a secondary which means it has access to [Primed Heated Charge], which is ideal for heat inherit. The forced cold proc from [Epitaph] will combine with heat sunder to strip armour, often allowing you to kill enemies outright without ever casting cold sunder. Playstyle would be to prime any eximus units first, and then nuke the room with Thermal Sunder.
Not familiar with heat inherit? Check out Ninjase's epitaph build and explanation: https://overframe.gg/build/376162/epitaph/heat-inherit-primer-epitaph/
For Kuva Ogris primer check out this build by CollateralKaos: https://overframe.gg/build/492670/kuva-ogris/gauss-thermal-sunder-nuking-companion/