Work in progress

WARNING: For players who have NOT finished The Second Dream and [War] Within quests, be aware that this guide might contain mild spoilers.

Eidolon budget build

tl;dr: Beginner friendly, just hit 4 every 30-60 seconds to heal and buff up everyone in a 50m radius. If you have spare energy, hit 3 for extra survivability.

This build's main purpose is to keep the Eidolon Lures, your squad and yourself alive throughout the whole fight.
In order to make sure the lures are in heal and Eidolon-tethering range, I usually fly around and grab all/most of them myself as soon as I arrive on the Plains.

Optimization and variation:
Depending on your squads setup and proficiency, you can modify this build as you wish.
This basic setup does a good job on any skill level.

• In most squad setups, your go-to aura for Eidolons is [Corrosive Projection]. You can add another Forma or Aura Forma if you want to. But this kind of minmaxing would only be necessary if you're aiming towards tridolon speedruns. Physique will increase your whole squad's survivability.
• [Power Drift]'s main purpose is to occasionally [Protect] you from knockdown effects. Since you achieve Blessing's max damage reduction without it, the extra 15% strength is not required for this build. You can replace it with [Coaction Drift], Speed Drift, (Primed)Sure Footed, Handspring, or even Aviator.

Arcanes are recommended but never required. Use what you prefer/own. In case of doubt, put a Nullifier and Momentum on any frame/build you wanna fight Eidolons with.

Focus schools:
I'd recommend utilizing Zenurik's Energizing Dash to keep your energy level sufficiently high. As an alternative, Vazarin's Mending Unity increases your affinity radius, thus increasing the range of your Blessing (4) to 60m. For speedruns, you'll either use Madurai's Void Strike or Unairu Wisp.

More Eidolon builds:

• Chroma (damage)
• Harrow (support/damage)
• Volt (damage)
• Rhino (damage, beginner-friendly)
• Oberon (support/healer)

Questions? Feel free to message me ingame or via Discord. :)
Warframe tips and beginner's guide here.