As a Dojo Frame, Banshee can be obtained extremely early in the game, although she has an unfortunate reputation as being very squishy and difficult to play. Contrary to her reputation, with a very small investment, she is one of the most in-control and chill CC/debuff frames.

Executive summary for people who don't want to watch the video and don't need a build demonstration: per my other post on survivability strats (https://beehaw.org/post/586396), we'll be using a Condemn build, replacing Sound Quake, and a Resonating Quake Fractured Blast HCAB (FBHCAB) build, replacing Sonic Boom.

FBHCAB build: https://overframe.gg/build/483482/banshee/tanky-lich-killer-banshee/ Swap Sonic Fracture for Resonating Quake, put FB or Lycath over Sonic Boom.

Condemnshee build: https://overframe.gg/build/483498/banshee-prime/no-brain-banshee-no-key-shield-gate/ For Duviri, swap Equilibrium for Streamline and fish for some energy economy decrees, to taste.

• Apollo SP demo of Condemn build: https://youtube.com/live/d58ij63H8C0?feature=share
• Hieracon demo of Quake build: https://youtube.com/live/_UOj-2l35yE?feature=share

Let me know in the comments if you would like demos of other nodes.

Not sure how well-known this is, but there's a fun interaction that happens in Circuit with certain abilities and the Deadly Decrees intrinsic.

Certain abilities are coded as projectiles, which you can check here: https://warframe.fandom.com/wiki/Arcane_Arachne. These abilities will scale off Deadly Decrees; they will also scale off "weapon enchant" type abilities, notably the Nourish helminth.

I've personally taken advantage of this with Final Stand on Styanax, Flechette Orb on Vauban, and Antimatter Drop/Antimatter Absorb on Nova.

While it's not developed by DE, it is published and supported by them, so I expect a lot of Tenno will have their eyes on it. I know from the beta I met a lot of other Warframe players.

Prior to Duviri, I put in some time acid testing boilerplate builds to get all my frames to scale into SP Circuit. I'll summarise the work here. I'm happy to answer any questions in the comments. Hopefully this will be of some use!

As a bonus, none of these require energy->shield mods or Decaying key, although using either or both adds an extra layer of survivability.

Infinite Scaling

Condemn helminth! Easily the comfiest and most reliable way of shield gating, as it CCs enemies and shield gates most frames in just two or three targets affected. The ability has a "soft" slam animation that has reduced priority over double jump and parkour, so casting during a double jump or bullet jump will keep you airborne. It's also a one-handed cast so does not interrupt reloads, and you can shoot mid-cast.

The important requirement is that you need to compensate range or strength on Overextended or Narrow Minded builds, or use the next helminth option.

Pillage helminth. Unlike Condemn, provides absolutely no CC, so I only recommend this on frames that have some kind of innate CC such as a slow, distraction, confusion, etc. Also a full-body cast so it prevents movement and other actions, and comes in at twice the casting cost.

Infested

The heck faction... until now. Silence helminth completely reduces them to melee, which should not be a problem with Warframe movement. Just don't get in a slap fight with any Disruptors or Toxic Ancients (or Venomous Eximus).

Silence prevents grapple hooks and Osprey clouds, as well as all Eximus casts. The only remaining mechanics are the Ancient stretch arm attack and MOA goop and clouds, but the MOA attacks do fixed low damage, so no biggy.

I just want to face tank to level 300

Health Conversion from Simaris, Arcane Blessing from Conjunction Survival, and your choice of Fractured Blast (same build constraints as Condemn) from Citrine, or Lycath's Hunt from Voruna (preferably don't dump stat Duration). Frames with inbuilt DR can go quite a bit farther than that, but even Banshee or Gyre can facetank with HCAB strats.

But I'm Inaros or Lavos

This section is theoretical, since I don't have Trickery.

Desiccate, Ophidian Bite, and Dagger heavy attacks force finishers, so you could use this with Arcane Trickery to stay invis. Otherwise possible helminths are Resonator (from Octavia), or Shooting Gallery (from Mesa) + Muzzle Flash augment.

In terms of community usage stats.

I really like Banshee, but I was shocked to learn she was at a mere 0.53% usage on last year's published stats. I'm also really fond of Yareli and Gyre.