Introduction

This is a build meant to take advantage of [Koumei]'s immense benefit of the Mecha set, alongside some health orb fueled bulk to give her plenty of sustain deep into steel path endurance. Paired with the right decrees, she can keep health tanking further than any other warframe, and can scale extremely well if she rolls the armor-to-strength decree with a good Helminth ability.

Mods

• [Mecha Empowered] is our aura of choice, allowing [Koumei]'s various random statuses to double dip their damage on the [Marked Target], then spread them to nearby enemies, while Mecha Pulse gives Koumei a large amount of armor upon spreading said statuses.
• Boreal's Anguish is here to make wall latch and airborne kill challenges easier. Flexible
• [Health Conversion] gives us a much larger armor value than would normally be possible, even with the Umbral set, at the cost of needing to constantly generate health orbs to keep it up.
• Adaptation is here to help with health tanking.
• [Archon Stretch] is the only range mod we have here, since [Koumei] realistically doesn't need that much range in practice, and the energy sustain is nice. You can run Overextended here instead if you want a bit more range at the cost of less upfront strength
• [Archon Intensify] gives us a total of 60% power strength when a heal from Omamori goes off. The extra 30% can be a bit inconsistent but its nice to have. Flexible
• [Archon Flow] gives us more energy to work with, and gives us a very tiny chance for an extra energy orb if a cold string from Kumihimo kills someone. Flexible for Primed Flow or Blue Archon Shards
• [Equilibrium] can be used for energy sustain. Has synergy with the health orb decrees. With Arcane Impetus giving a lot of efficiency, I find that I don't need this for sustain
• [Archon Continuity] for extra duration on Helminth abilities, as well as some extra armor strip whenever you roll toxin on Kumihimo and Bunraku
• [Omikuji's Fortune] is very nice for cycling your decrees faster. You'll have to [Sacrifice] something to make it work, but it's very worth it. I've replaced Equilibrium with it since energy has never been a huge issue for me, but Archon Continuity also works as a sub.
• [Archon Vitality] doubles heat procs applied by Kumihimo and Bunraku, while also giving [Koumei] more upfront bulk. I don't have it on by default here, but sometimes I'll put it on over [Archon Intensify] since 60% strength isn't a lot when you roll into Forified Will.

Arcanes

Arcane Blessing gives us a very large health pool to work with, at the cost of having very little health at the start of the mission.
Arcane Impetus gives [Koumei] a lot of strength and efficiency for just casting her Kumihimo or Bunraku on a somewhat regular basis.
Arcane Arachne can also be good to boost your weapons

If you [Hate] relying on health orbs for your tankiness, you can opt for an alternative setup with [Archon Vitality] and Arcane [Guardian] instead of [Health Conversion] and Arcane Blessing respectively, but you will be a decent bit squishier this way, so be wary.

Helminth

Generally, I don't run her with any Helminth abilities, but there are a lot of good choices, given that with this build, if you roll into Fortified Will, any ability will have a ludicrous amount of strength behind it. If I am subsuming something, I'll subsume over her 1, Kumihimo, since it and Bunraku are a bit reduntant. Survivability subsumes can go over her 3, Omamori, instead, if you'd like.
Some highlights include

• Roar - Faction weapon bonus, also double dips on her random status effects on her abilities.
• Eclipse - Option between damage reduction and weapon damage
• Gloom - fun survivability option
• Wrathful Advance - good for melee-focused setups

Archon Shards

Casting Speed is really nice for [Koumei], I personally run 2 Tauforged Amber Shards for that.
One Starting Energy shard is also really handy, to allow you to cast both Omikuji and Omamori at the start of a mission
The other two slots are flexible. Some options include:

• Two normal Emerald shards for max Corrosive stacks, or one Tau Emerald for 98% strip
• Topaz or Crimson shards for secondary crit chance
• Violet or Crimson shards for melee crit damage
• Crimson shards for ability strength
• Azure shards for energy max
• Violet shards for the [Equilibrium] effect

Loadout

Generally, [Koumei] is pretty flexible with what weapons you run on her, with the only thing you need to worry about having is something that can headshot, as some decree challenges require it.. Look into using some incarnon weapons on her, especially the Zariman ones like the [Phenmor] and [Laetum].

If you really want to squeeze every bit of damage out of her, look to run weapons that scale multiplicatively with [Condition Overload] type effects, since her Kumihimo and Bunraku apply many random status effects. See this wiki page for some examples of what weapons work well.
My go-tos are the [Felarx] and [Prisma Angstrum] Incarnon, but nearly anything on that page will do really well with her

The other thing to note is that it'd be good to have a melee that is good at doing finishers, as a few decrees require it to activate their effects. To that end, I like using the [Innodem] and [Prisma Skana], as they both have special effects on finisher. Daggers in general can run [Covert Lethality] for extra finisher damage, but I feel it is generally not necessary.

For your companion, you're going to need a dog of some kind to round out the Mecha set. To that end, I recommend the [Medjay Predasite], as one of its abilities opens enemies to finishers, which is handy whenever you roll into some finisher decrees. All Predasites also have enough shields to where you can run [Reinforced Bond] alongside [Calculated Redirection] for more fire rate, if you desire. Here is my [Medjay Predasite] build.

Your focus school can be either Naramon or Vazarin, as both can open enemies to finishers with their 2nd abilites. Madurai is fine too if doing Zariman content.