ALL MY BUILDS FOCUS ON USING UNDEAD WARFRAMES WITH WEAPONS FITTING THEIR THEMES. THEY MAY NOT BE THE ABSOLUTE BEST OPTION FOR IT, BUT I STILL MAKE SURE THEY'RE MORE THAN VIABLE ENOUGH.

INTRODUCTION

The main focus of this build is to kill Liches and Sisters as effectively as possible. To do so we follow these steps:

0. First you need to get your progenitor. For liches go to Cassini in Saturn and kill enemies asap to spawn it. For sisters go to Hydra in Pluto and get to the granum void asap, using a [Xoris] to get enough points to spawn a sister. After you down them, if they don't have the weapon you want, leave and repeat. The element depends on the warframe you use to defeat them.
1. On a regular mission or in the last fight change to your operator and cast an ability to trigger Molt Vigor, then wait for Molt Efficiency to get to 36% and cast Gloom for that 95% slow, then let it expand. While doing that you can shoot once and reload to trigger [Reinforced Bond].
2. Cast Silence to paralize enemies. Re-cast whenever it runs out.
3. Kill enemies and collect murmurs. Cast Sonar to either shield gate or kill tougher enemies faster.
4. When fighting a Lich/Sister: get as many galvanised and arcane stacks as you can on your main weapon. Let [Shade Prime] make you invisible. Cast Sonar as many times as possible. Cast Magnetic Flare to shield strip them, then shoot. If fighting a Sister you can also armour strip her with Caustic Strike.

BUILD SPECIFICS

FOCUS SCHOOL

We use Unairu for this build. The nodes we care most about is:

• Poise: This makes us immune to slow, stagger, and knockdown effects, which means we don't need to run Primed Sure Footed. Just make sure to switch in and out of operator every 40 seconds or so.
• Stone Skin: This gives us 200 more armour. While it's not enough to really matter, it's still a little bit more survivability, so it's appreciated.
• Magnetic Flare: This gives us an option to completely strip shields. It works on hounds, Liches, and Sisters.
• Caustic Strike: This gives us an option to completely strip armour. It works on hounds and Sisters, but Liches are immune.

ARCHON SHARDS

• Crimson Archon Shard:
  +10/15% Ability Strength x3. This is mostly to make up from the loss caused by [Overextended]. It's also so that we can max out Gloom's slow cap.
• Amber Archon Shard:
  +25/37.5% Casting Speed x2. Since we'll be recasting Silence and casting Sonar multiple times this ends up being a rather good quality of life choice. Sonar in particular has a rather long casting animation, so we want to make it as short as possible. This gives us up to 1.75x casting speed.

STATS:

• STRENGTH: We use [Precision Intensify], [Transient Fortitude], Molt Vigor, and three archon shards. You need 272% ability strength for Gloom to hit its 95% slow cap, and we start up with 140% ability strength at base because of the loss from [Overextended]. [Precision Intensify] gives +90% ability strength to out fourth ability, bringing us to 230%. To make up for the 42% missing we cast an ability with our operator, triggering Molt Vigor for that +45% ability strength.
  The other ability we care about that relies on ability strength is Sonar. At 140% ability strength Sonar does a damage multiplier of 7x. Keep in mind, Sonar can be cast over and over and stack onto itself, so when fighting the Lich/Sister you're hunting you might as well spam that ability instead of only casting it once.
• DURATION: We use [Primed Continuity], [Augur Message], and Molt Efficiency. Duration affects most of the abilities we use, making Sonar's weakpoints last longer, making us able to keep Silence up for longer, and reducing the energy drain of Gloom.
  At max Molt Efficiency stacks we have 187.5% duration, which makes each Sonar cast and Silence last 56.3 seconds each, while Gloom would drain 0.28 energy per enemy, up to 2.8 energy per second.
• RANGE: We use [Overextended]. we want a bit of range, but not too much. The range of Silence is bigger than the range of Gloom, so if we increase the range too much the difference between the two will also increase, and Gloom won't be able to slow down the stun from Silence... or that's what I'd like to say. From constant testing hunting liches and sisters I've ended up in situations where enemies are just outside your range way too many times, and when outside your gloom range it doesn't matter if they're hit with silence or not, they'll be shooting you like crazy. Because of that I decided that 190% is a much better range for gloom, and altered the entire build accordingly so that you could still get the proper amount of ability strength and efficiency, sacrificing only some of Sonar's damage.
• EFFICIENCY/ENERGY: We use [Preparation], [Primed Flow], and [Streamline]. [Primed Flow] gives us a large max amount of energy, while [Streamline] makes abilities cost less. The only way you could ever run out of energy is spamming Sonar in place non-stop for a good minute or two or spending around 4 or so minutes at max drain with gloom without getting any energy back.
  When it comes to [Preparation], you want to start with full energy more than anything to keep Gloom up at all times and be able to cast other abilities from the beginning.
  The calculation for starting energy is:
  Base Starting Energy + (5 x (Mod Capacity Left + Extra Aura Capacity)) + (Total Energy x [Preparation] Multiplier).
  [Banshee Prime] starts with 125 energy. Our aura gives us 14 extra capacity, and our [Preparation] gives us a 73% multiplier and leaves us with two capacity left. That'd make our calculation be:
  125 + (5 x (2 + 14)) + (755 x 73%) = 756.15. which is max energy.

LOADOUT:

• PRIMARY: We use the Tenet Arca Plasmor. This will be our main damage dealer for regular enemies, thralls/hounds, and Liches/Sisters. every shot has a massive range, working as a pseudo AoE, while still benefiting from mods like Galvanised Savvy. Try to stack multishot as much as you can before hitting your Lich/Sister. When dealing with hounds, Liches, and Sisters remember to also cast Magnetic Flare to get rid of their shields immediately.
  I chose this weapon thematically because the projectile looks like a massive sound wave.
• SECONDARY: We use the Sonicor. This weapon is mostly here for aesthetic. The only real reason we have to equip it is to slap Augur Pact in it so we can properly shield gate.
  I chose this weapon thematically because it's all about sound.
• MELEE: We use the Stropha. This is a good alternative weapon, specially whenever you need to carry something like in excavation and mobile defense missions. You should be able to 1-shot thralls, hounds, and eximus units with it. Mine's set up specifically to 1-shot hounds without needing to bring their shields down.
  I chose this weapon thematically because it's the only melee that causes shockwaves.
• COMPANION: We use Shade Prime. Originally I was thinking of using [Dethcube Prime] for the energy drops, but the main issue is that using sentinel weapons will end up triggering the damage attenuation from the Lich/Sister, making them harder to kill them. Instead we focus on both survivability with Ghost, and more buffing with Ambush and both Tenacious Bond and Reinforced Bond.
• PARAZON: Because we will constantly mercy kill enemies when hunting liches and sisters we use the mods Blood for Ammo and Blood for Energy on our Parazon, so we auto reload and get some energy with every mercy kill.

GAMEPLAY ELEMENTS:

• SHIELD GATING: We use [Brief Respite], [Augur Message], and [Augur Pact] on our secondary weapon. Because of [Catalyzing Shields] your shields will get reduced to 20% of their total, which is 74 shields for [Banshee Prime]. the mods we use give us 150 + 40 + 40 = 230% of the energy we used as shields. The ability we'll use for this is Sonar, which is our most spammable ability. At 35 energy per cast it'd be 35 x 2.3 = 80.5, effectively filling up our shields entirely no matter what.
  The reason why we want low max shields is because of how shield gating works with [Catalyzing Shields]. when your shields are depleted you gain 1.3 seconds of invulnerability. If your shield starts regenerating and goes down again before it can fill up fully, however, the invulnerability will only last 0.3 seconds. With these mods we make sure to always fill up our shields to get max invulnerability time.
• SURVIVABILITY: We use Poise to prevents AoE explosions from suddenly knocking you down, which would be a death sentence at higher levels.

BONUS BUILD - 0 FORMA OPTION

So, if you want to test this build but are too worried that you won't like it and will waste forma on it, here's a 0 forma version of the build for you to test. 0 Forma builds always have compromises, but I try to make them as close to the original to give an accurrate representation when testing.

MOD CHANGES:

• [Brief Respite] to [Shotgun Amp]: The polarity doesn't match Brief Respite, so we gotta replace it with anything else. I put a mod to benefit my primary, but you can slot in whatever you wish.
• [Catalyzing Shields] Removed: Since we can't properly shield gate anymore this mod becomes useless, sadly. It only takes up space.

And that's it! Besides the aura mod and one removal all the mods are exactly the same, just in different spots since we can't change polarity positions with 0 forma. While even squishier than before due to being unable to fully shield gate, it's still a pretty good alternative that keeps the same amount of power as the original. If you're worried about survivability you can replace [Augur Message] for [Rolling Guard] for some invulnerability.