Use Roar if you like boosting yourself AND your squad up a bit of damage.
Use Eclipse if you want a MUCH bigger damage boost that focus directly on you instead if you aren't too concerned with buffing your squad alongside you.

Heavily Recommend Pairing w/ This -> Universal Nikana Config & This -> Daikyu Config | Yes That [Daikyu] Config IS Unfinished So Feel Free To Modify It's Damage However You'd Like But It's Main Purpose Outside of Damage is Healing Due To The Amalgam Mod- and THAT Combo Synergizes VERY Well w/ [Hunter Adrenaline] For Virtually Limitless Energy Gain

Remember to have fun! It truly is great, I've gone through high levels of Steel Path Defense, Survival, Interception, etc with this config- its not designed to be the best on it's own. Which adds a challenge.

3 Umbral Mods make a tankier Umbra- Adaptation isn't worth having on unless you either-
1. Don't Use An Augment Mod
or
2. Have Good Control Over Your Shield-Gating Which Leaves You Not Finding Any Importance in 2 Augur Mods- Freeing Up An Extra Slot. I'd say take off Rolling Guard but it's better than Adaptation on it's own, and 1 Augur mod is just fine for shield-gating if you wanna pair up Adaptation with Rolling Guard. So yes the loss in Range or Strength can be felt a tad bit for sure but it's not really troublesome.

Hunter Adrenaline makes a great energy gain- and with how fast you can kill and the crowds you can take out with this set, you can refill your health rather quickly making it not too much of a worry in tense situations.

Rolling Guard is self-explanatory- but use it well. Shield Cracks- Roll- Radial Howl for Crowd Stun for Shield Refill from Augur Mods.
If Using the Madurai Tree -> Transference Into Double Void Sling After Activating Rolling Guard (or before rolling if you wanted) To Activate the Sling Strength Buff -> Crowd Stun/Blind with Radial [Howl], Brief Stun with Radial Javelin & getting a damage boost off of it due to the [Furious Javelin] augment that is also slightly buffed due to the Sling Strength buff boosting you Ability Strength

( Augur Secrets + Augur Reach ) is a great synergy for Shield-Gating as well as the boosts to Ability Strength and Range of course- using abilities ideally while Rolling Guard is active to replenish shields during the invulnerability window. Allowing near infinite Shield-Gate potential. I am personally using [Adaptation] because it makes any frame MUCH more tankier, especially Umbra with all 3 Umbrals on for the Health and Armor stack.

Furious Javelin has PHENOMENAL potential in crowds- and with the boosted range from your Augur mod (especially the potential range boosts from Relic Farms) you can gain a quick and easy Melee Buff of over 1000%, 2000%, 3000%, etc- and if combined with a good Primer like Cedo, Nukor, or Kuva Nukor, it makes an even more insane damage boost to a Melee Config featuring Condition Overload.

Arcane Fury is self-explanatory and procs VERY often
Arcane Strike is self-explanatory and procs VERY often. It says it's only 15% chance- but think of how fast you are striking with your [Nikana] (even slower heavy blades) and how many combos you're throwing out, EACH individual hit having a chance to proc the 60% speed boost. That constant movement creates virtually 100% chance, always retrying the proc of that 15% chance with EVERY single strike- each coming out in less than a second. I'm speaking from experience- and many others know the Arcane too, of course. I'm not acting like this is some unknown gospel- but yeah it procs VERY often and makes Quickening a better choice than Berserker Fury on a [Nikana] due to it's Combo Count Chance synergizing with Blood Rush.

(You Can Equip A Decaying Dragon Key for Shield-Gating But They Are Not A Necessity To The Build- So If You Don't Like Decaying Keys Then No Worries!)
([Furious Javelin] is interchangeable with [Chromatic Blade] when complimented with a synergizing [Exalted Umbra Blade] config)

Unimportant TL;DR + Who Asked AKA "Why the paragraph at the bottom?"
P.S.
I see people argue very ignorant and needless points about the workings of the damage, status effects, percentages, etc on any Warframe build they aren't immediately familiar with whether it's an actual Frame or a weapon config. Im not saying those workings are bad btw, just that people argue points that are irrelevant or only situationally relevant which is needless- and I'd like to squash any potential of that beef here immediately. This build has taken me through very high level areas of steel path and I literally only use my [Nikana Prime]. No primer, no primary, no secondary. You cannot tell me this build is objectively bad especially if you're just button mashing and expecting the mod config to carry you, I have lasted well over an hour or two in Steel Path with this- you have to move well, use rolling guard well- take advantage of your roar/eclipse, blind, javelin, and shield gate well- and attack well. Its a great build but also a test of skill in a way- I don't want to remove the game's death mechanic entirely, that's too easy. It isn't meant to carry you and let you just sit at your desk like the guy from the WoW Episode of South Park- barely putting effort to even shift around in his chair. You CAN meathead the build and just mash aimlessly on whatever you're wanting to kill, but you'll very quickly see yourself dying a lot. This build will not be taking you to level cap- you will need good WEAPON CONFIGS to take Umbra to steel path- his builds alone cannot just immediately idle his way up to level cap by relying on his abilities. His Umbra Blade is amazing but you'd be surprised how much my [Nikana Prime] alone has been a better pick for crowd situations. Without using Furious Javelin even. Both Umbra Blade and Nikana Prime are amazing- and paired with a Primer and/or Damage weapon(s) in the form of Primaries and Secondaries- they can do even HIGHER amounts of damage obviously. But please do not immediately look at this build as "Oh another overframe build its def trash" just by looking at the mod config and not even testing it. People who test configs and point out flaws is valid- they LITERALLY tested it and saw results for themselves- but just immediate shade or hate with very minimal attention or testing is just unneeded and unwanted- I see that shit get toxic so fast in the Warframe community and dont wanna see people doin that on good/fun/funny/test/etc builds that I do and put out there. Also I know Overframe has a meme reputation- but I like it's layout so I use it. I get this game has a literal objective sense of "yes you can argue builds due to immediate comparisons that exist" but why make it hostile and stagnant with no progress? I already said it wont take you to level cap on it's own- so don't expect that and go in thinking its the God of all builds. I could end up stumbling upon myself creating a God config, you could as well, or your friend, or the randoms you meet in lobbies. But I don't claim this to be one of those- so dont get all oddly hateful
Real critique on any/all builds I make is well appreciated! I really enjoy testing in this game so feel free to point things out to me if you're actually testing the builds yourself!

Test the build yourself before bashing- actually focus on your gameplay especially if you're melee only- use good primers if that is your playstyle- real critique is always welcome from people who do REAL tests and not just "did a random mission- meh- its whatever"