With the power of multiplicative effects, you too can kill one unfortunate Mecha-marked enemy to kill everything within 30 meters.
Also you're Lavos. Mostly you're Lavos for the sheer variety of effects, ability to roll over most enemies, and, oh yeah, the almost tripled status duration. That too.

Use of a Kitgun with Residual Boils is recommended.
Paired Companion build: Vizer Predasite - Tenno's Mecha Hound

How-to/general gameplay loop:

• Whenever an enemy is Mecha-marked, kill it as quickly as possible, applying at least one damaging status effect to it. Doing so will affect all enemies within 30 meters of it with its status effects - of which the damaging ones were already increased twice by Mecha Empowered - which will, without exception, kill anything weak to status effects.
  • Mecha Pulse's effect is granted to whoever strikes the killing blow, regardless of if that is you, your operator, an ally, an ally's operator, or a specter, with companion kills passing the effect on to their owner.
  • The Mecha set bonus will trigger regardless of if you personally kill the Mecha-marked enemy, and damage done by its status effects counts as your companion's damage, allowing it to trigger Mecha Pulse for your benefit.

• This will not serve as a significant guide to Lavos himself.
  • Cast Vial Rush(your 2) as often as possible to cover areas in Cold procs.
  • Cast Ophidian Bite(your 1) on groups of enemies or when losing health.
  • Cast Catalyze(your 4) whenever a group of enemies is near you and you've already recently triggered Mecha Pulse.
  • Cast Transmutation Probe(your 3) at groups of enemies whenever Catalyze(and preferably Ophidian Bite) are on cooldown.

Why this choice/other options:

• No Helminth Replacements - Lavos cannot infuse his abilities using a replaced ability, which is extremely painful for all abilities except maybe Catalyze.

Tips and Tricks:

• The Mecha set bonus works in several unusual ways:
  • It does not apply all of the status effects at once - if there are more than two stacks of a status, it will apply that status at a rate of two stacks per second, which noticeably extends the duration of the effect in general, especially for Heat status effects.
  • The status effects applied through the Mecha set bonus are treated as originating from your Companion, but despite this, they benefit from Lavos's extended status duration. Depending on the status of Molt Augmented, with the exceptions of Corrosive(8s > 22.56s to 25.44s), Radiation(12s > 33.84s to 38.16s), and Void(3s > 8.46s to 9.54s), the status effects applied this way will last 16.92s to 19.08s.
  • Note that status effects double dip on damage with Mecha Empowered, in the same way as Faction damage mods - which Mecha Empowered stacks multiplicatively with. If you can spare a slot for a Bane, Cleanse, Expel, or Smite mod, or have access to an allied Rhino(Roar is a Faction damage effect!), this can massively increase your damage, and the damage of allies, against Mecha-marked enemies.
  • There is either a bug or something very unusual going on with the damage calculation of the applied status effects - it seems, through some testing, that the damage of each individual damaging status is equal to the total damage of all of the original status effects.
    • This means that, with ten 560 damage Slash statuses, the Mecha set bonus would be applying two stacks of a 5600 damage Slash status every second for five seconds, which lines up with the observed effect of activating it - that everything in range dies extremely quickly.

• When killing a Mecha-marked enemy, try to make sure to be in a group of enemies; Mecha Pulse originates from whoever killed it, and not the Mecha-marked enemy.
  • This applies even if you personally aren't running this build - if you see a glowing Kubrow face above an enemy, being in a group of enemies before you kill it will grant significantly more armor.
  • Killing a Mecha-marked enemy while Mecha Pulse's bonus is still active will override the current bonus with the new bonus, even if that is less armor. This will usually only matter if there are multiple Mecha mod users in a single squad.

• You can cancel Vial Rush earlier than you can recast-to-cancel by jumping as soon as you activate it, which lets you cover small areas with many vials for increased damage.

• Remember to select elements that are most effective against the factions you're facing, but don't forget that, with 282-318% Status Duration, you have ample time to select other, less-used elemental damage types rather than just Heat, Viral, and Corrosive - Cold, Gas, and Radiation can have significant effects with the extended status duration.

Recommended Archon Shards:

• 1x Ability Duration Crimson Shard, to very slightly improve duration. This adds 0.8 seconds to Corrosive statuses, 1.2 seconds to Radiation statuses, 0.3 seconds to Void statuses, and 0.6 seconds to all other statuses. If this shard is Tauforged, this is improved to 1.2 seconds, 1.8 seconds, 0.45 seconds, and 0.9 seconds, respectively.
• 2x Ability Strength Crimson Shard, to make Catalyze hit even harder.
• 2x Casting Speed Amber Shard, to make everything cast faster. If one or both of these shards are Tauforged, Lavos's abilities will cast exceptionally fast. It's a free [Natural Talent] and everything wants it.