Disclaimer:

This build will not perform well solo due to survivability issues, and the fact it's a support build. For solo purposes check literally any other build on this site.

What is the goal of this build?

This build envisions [Equinox] as a support with Power strength for the whole team. She can do that thank to her 3rd ability in day form, Provoke (for details , the link to Provoke's wiki page is down below). It can also fill the secondary purpose of nuking, but without an armor-strip it is not really effective in Steel Path.

Description:

The build was made in such a way that Metamorphosis is subsumed over. That way [Equinox] will be forced into one of her 2 forms Day or Night(depends on emissive color). This build uses a brighter emissive color to force [Equinox] into day form, as none of her nigh form abilities are needed in this build. Furthermore, switching to night will lose Provoke's strength bonus which is the entire purpose of the build. Also, [Rage] (ability not mod) can be used to increase the damage taken by enemies increasing the damage charge on both Provoke's augment and [Maim]. For Provoke to hit maximum potential, [Equinox] needs 250% strength. That is not an issue to mod for, but breaks the viability of building up the augment's buff( read the section about the augment for details) since the range mods would need to be sacrificed. The build has 209% Ability Strength and Empower provides the additional 50% necessary for un-augmented Provoke to [Reach] its cap(from 20% extra strength at base to 50% additional strength at cap). Duration and Efficiency both need to be positive so both Provoke and [Maim] don't consume too much energy. In this case a rank 9 [Narrow Minded] would work better but it's not mandatory. Range needs to be as high as you can get it without hurting strength. This opens up the secondary purpose of nuking and will give a larger area of effect for Provoke's aura .
Now, let's cover the augment that this build uses. [Peaceful Provocation] is the augment for [Equinox]'s 3rd Ability Pacify&Provoke. Since the build forces [Equinox] in day mode, I'll only cover the augment's effect on Provoke. When Provoke is active, damaged enemies in Provoke's aura increase the strength provided by Provoke by an extra 15%(base) capping out at an additional 30%(at 200% Ability Strength). The enemies inside Provoke's aura can be damaged from any source, including allies, to provide the extra strength, therefore a hefty range is recommended when using this augment.

Flexibility:

Although strict in what the build requires to function, there are some flexible spots:
1. Aura Mod slot. [Enemy Radar] is a very strong option in the aura slot if none of the squadmates use [Animal Instinct] or its prime version. Besides that, there is no mandatory aura so that slot is flexible.
2. Exilus Mod slot. In order for this to work we need something to replace [Power Drift]'s 15% Strength increase. Since the build needs 200% to work, one Crimson Archon Shard, tauforged or not, will be enough to open this slot up. My recommendation would be [Cunning Drift] to increase the range of Provoke and [Maim], but ultimately it's up to you.
3. The 8th mod slot ([Augur Reach]). Although this build needs as much range as possible, this slot is flexible for a survivability mod such as [Rolling Guard], [Natural Talent] which is very useful if you don't have an Amber Archon Shard on [Equinox], or an Ability Efficiency mod such as [Streamline]. Duration simply needs to be positive and Strength is already high enough so Efficiency is the only stat boost you can put here.
4. The 2nd Arcane slot. Energize and Steadfast are the best arcanes to use, but Steadfast can be swapped out if you really feel the need to.

I hope this build has been of use to you and your fellow tenno, and I wish you good RNG and goodbye.

Link to Provoke's wiki: https://warframe.fandom.com/wiki/Pacify_%26_Provoke#Day_Form