Yes, this build is viable and not a meme. Although it is not for the faint of heart. I recommend looking under the ALTERNATIVE OPTIONS section near the bottom of the page to look at how to build if you don't have certain items like Arcane Energize or [Primed Sure Footed] yet.
This is an extremely long build that has many requirements. In order to achieve max strength, it is required to use 4 Forma and 3 Umbra Forma to fit on everything. If you're without [Primed Sure Footed], which I imagine most are, you can instead use 6 Forma and 2 Umbra Forma. It also requires reaching rank 5 with Solaris United, rank 3 with Ostron, rank 3 with Entrati, and rank 1 or 5 with The Holdfasts, depending if you use Molt Vigor or Molt Augmented. In addition, you need access to the Railjack.
To explain the strength variance in the title- 900% strength is obtained by swapping out [Primed Sure Footed] for [Power Drift], and Arcane Energize with Molt [Vigor]. 725% strength is if you drop [Augur Secrets] and a single Pax Bolt, as well as use Zenurik over Madurai. As you'll read later on, I do strongly recommend at least a single Pax Bolt.
This build is possible in any mission that doesn't restrict you from accessing your Gear Wheel and allows you to Mercy kill. Although the typical issues with [Wisp] are still prevalent, such as not working well if the team is moving around a ton. That means Defense missions are your best friend, with Survival a touch behind. Reaching max numbers consistently while moving is near impossible. There are a total of 8 requirements to [Reach] at a single time for max strength. 6 can be made essentially passives, and 2 of them must be done within a 4 second limit. If you select conditionals, you'll see it only reaches 490% so far. The list of conditionals you must meet are listed below. The builds for these are linked at the bottom of the page. Additionally, if you are a newer player, there is a budget build and guide linked as well on how to obtain and construct the build.
1.) [Energy Conversion]. Just pick up an energy orb and keep buff in the background until needed. More below on how to facilitate this and make it a passive.
2.) [Growing Power]. Apply a status effect with a weapon. Again, see below for how to turn this into a passive.
3.) [Power Drain]. This one can be tricky. The longer the mission is, the easier this procs. All you need is to Mercy kill an Eximus and the buff will sit in the background awaiting use. I recommend using an Impact based weapon, like [Catchmoon], to apply Impact procs with. These will raise the threshold where you can Mercy kill units, making it easier. If that option isn't available to you, I recommend using Breach Surge after not shooting anything, then jumping in place waiting for the Mercy trigger. Jumping keeps your [Dethcube] from stealing the Mercy from you. To that end, also keep the [Nidus] specter elsewhere for the same reason.
4.) [Nidus] Specter. Summon the specter at the beginning and it will continue to link you, giving you a 1.28x multiplier to your strength. I recommend having it hold position where you want the Motes as to ensure Parasitic Link stays active. This is technically semi-passive however. It's possible the link breaks from distance or time. But it is very forgiving and easy to tell if it's active. If it does break, try having it Follow, then Hold Position again. If it is not shooting and you are closer than an enemy, then it can automatically link you. You can obtain specter blueprints from Rescue missions. Since the specter gets your buffs, as well as a Vapor specter having the same ability strength as a Cosmic specter, you can just farm Vapor specters for the x10 blueprint.
5a.) Hardened Wellspring. Have the Zenurik Focus School equipped, then swap to your Operator and press 1 to use Wellspring. Press 1 again to activate Hardened Wellspring, granting you and allies inside the Wellspring +20% strength.
5b.) Sling Strength. Have the Madurai Focus School equipped, then Void Sling twice to activate Sling Strength and gain +40% strength. If your timer runs out, just swap to your Operator and Void Sling again twice to reset the timer.
6.) Molt Augmented. Killing enemies gives a 0.24% strength boost, up to 250x, for a total of 60% strength.
7.) Pax Bolt. This is the timed requirement. The other 5 requirements need to be met before focusing on this. If you're going for double Pax Bolt, I recommend Haymaker+Splat [Sporelacer] and Tremor+Killstream [Catchmoon]. Using [Catchmoon] first then swapping to [Sporelacer]. But whatever works for you. This takes a lot of effort and good reaction times. Find a hallway or narrow path to trigger double as easy as possible using [Vitrica] glassing. Again, single Pax Bolt is perfectly fine.
8.) Repeat process again for second Mote. I recommend going for Haste then [Vitality]. It's important to note that you should summon the [Nidus] early and get good Motes down before going to max numbers. Make Motes better throughout the mission rather than trying to get everything before placing any.
So how do we support this gameplan? Well with the assistance of a few mods and Arcanes, we can push the build even farther.
A.) [Energy Generator]. This will require the use of [Dethcube]. This mod is slept on. Note that the [Dethcube] can fully kill rather than assist and it will still drop the energy orb to support [Energy Conversion]. Also, it drops an orb for every member in the party not just yourself. I truly believe this mod brings [Dethcube] to S Tier.
B.) [Verglas] or [Cryotra] companion weapon. These weapons can [Reach] 100% status chance. This means [Growing Power] is always up as long as enemies are near and you are not jumping.
C.) [Vitrica]. This melee weapon can use an aerial aim glide attack that turns enemies to glass for 7 seconds. This hard CC is incredibly helpful for getting double Pax Bolt.
D.) Zenurik or Madurai Focus School. Zenurik will increase the energy we get from pickups as well as give us Wellspring for extra energy and +20% strength. Madurai is also a good choice because it increases strength by +40% rather than +20%. However while Madurai increases damage, strength, and casting speed, it does not help in the energy department. If you feel yourself running out of energy consistently, use Zenurik. If you feel you have enough, use Madurai.
E.) [Sacrifice] + [Primed Regen] Combo. If allies can't get you, well no more Motes. That means going through it all again. Twice. To this, I say use these mods in conjunction and get 4 free revives every game. This, with your Motes, Wil-O-[Wisp], Breach Surge, invisible while jumping passive, and [Primed Sure Footed], will keep you from ever dying. Make sure [Sacrifice] is to the top left of Assault so that it orders to revive you before attacking enemies.
F.) Arcane Energize. This Arcane speaks for itself. This with [Energy Generator] doubles up Energy restoration and can even allow you to spam Breach Surges. What could be said about this Arcane that hasn't already been said?
G.) [Blood For Energy]. This mod is not even close to needed, but it comes with such little drawback that it's worth it if you have it. The Parazon doesn't hold contentious spots so it's kind of a "why not?" scenario. If you don't have it, don't worry.
STRATEGY AND PLAYSTYLE
Once the Motes have been placed, it can be fun to try and trigger max Roar every 40 seconds. It's possible, but it takes a very active playstyle. I have found it is not important to make Roar max. All I recommend doing before you Roar again is triggering Sling Strength/Hardened Wellspring. Roar should be just over 200%. You can try and meet the 7 requirements, but don't sit there trying to make it happen and leave your team without the Roar.
After your Mother Motes have been placed, which hold your strongest buff, place back up Child Motes across the room that you're in. You don't need to make these max, as they exist to refresh the buff for wandering players, as well as spam Breach Surge. If you're against Corpus or Corrupted units, which may have nullifiers, be careful to [Protect] the Mother Motes. You may even want to make your back up Child Motes at a decent strength too, just in case.
From here, use your Wil-O-[Wisp] and Breach Surge abilities in tandem with Roar to deal massive damage to enemies at an increased range. For those who are unaware, Breach Surge is a damage multiplier. As is Roar. These together allow you to triple dip in to damage, as Roar is multiplicative and affects every different source of damage. Roar double dips by increasing the base damage of your weapons as well as any procs of Toxin, Heat, etc. Using with Breach Surge, this triple dips by affecting the Breach Surge multiplier itself on top of the original source. This allows for insane damage in the multi hundred million. In addition to these synergies, Wil-O-Wisp and Breach Surge also work together very well. By casting Wil-O-Wisp first, the Surge Sparks of Breach Surge will appear on you and your Wil-O. This doubles your Surge Spark count from 20 to 40. Visually you still see 20 in the lower right, but additional Surge Sparks will be visible on screen spawning from Wil-O. Finally, use Breach Surge to teleport between your Mother and Child Motes. This doubles your Surge Spark range. Yes, this doubles Wil-O's Surge Sparks as well. Once put together, you get double the amount of Surge Sparks, double range, as well as near triple damage. Simply press 4, 2, 3, aimed at your Mote. Then shoot. Rinse and repeat. Remember, despite the tanked efficiency of 45%, your Deathcube is spawning energy orbs constantly, with additional energy from each pickup with Zenurik and Arcane Energize. You can spam this combo pretty generously.
First and foremost, I actually want to discuss what not to put on [Wisp]. More specifically, the mod [Adaptation]. I understand that the mod can be a valuable asset for survivability, but [Wisp] has so many tools to circumvent the need for this. The simplest one being her passive, allowing her to be invisible while in the air. Jump when you encounter danger and enemies will stop shooting you entirely. In addition to this, she also has Wil-O-[Wisp], which after activating a second time will make her fully immune to all damage and status effects for a short time. Enemies are also blinded by Breach Surge before the Surge Sparks ignite. All of this added on to her Motes giving her 2000 max HP with 200 healing a second, and Shock Motes stunning enemies near, means that [Wisp] already has insane survivability and maneuverability on the battlefield. She is her own tank. Do not use [Adaptation]. Just jump.
On that same note of what not to use, I hear many people say using the Umbra Mods in conjunction isn't worth it. I highly disagree with that opinion. Because they all better eachother, the value you get for them is unprecedented. I would be hard pressed to find a mod that gave me 770 Health, 96 Armor, and 11 Ability Strength. Or 220 Health, 337 Armor, and 22 Ability Strength. A key difference here between using the Umbra Mods for survivability rather than [Adaptation] is that increased Health and Armor help you against being one shot, whereas you need to take multiple hits for [Adaptation] to take full effect. With the healing provided by Motes, one shots are really the only thing that bring you down. I say build to save yourself from things that actually kill you. It may take 3 Umbra Formas, but it's worth it.
If you're without [Primed Sure Footed] you can use [Sure Footed], [Power Drift], or Fused Resovoir. However, using Fused Resovoir may aggravate some allies due to Shock Motes slowing enemies too much. Be flexible with your teammates and swap off Shock Motes if someone requests.
Finally, while the third Umbra Forma allows everything to fit, it also allows you to swap [Augur Secrets] for any mods with cost of up to 11 in the flex slot if you want to expirement or try a different mod out. I recommend [Stretch] if you're happy without [Augur Secrets].
Elemental Ward from [Chroma] is another great option for [Wisp] when using the Toxin element. This grants Toxin damage to weapons as well as faster reload. Something [Wisp] can struggle with due to emptying clips so fast from the Haste buff. If you commonly see Roar from other party members (no it does not stack) or want to use a different option, this is the next best. I recommend using the [Everlasting Ward] augment to allow allies to keep the buff longer.
Another unused option is Warcry from [Valkyr]. This increases you and your allies armor, slows enemies, as well as increasing attack speed for you and your allies Melee weapons. This is pretty redundant, so I think this more of a meme, but the use of the [Eternal War] augment allows it be active theoretically forever. This would free up the [Primed Continuity] slot as the added duration is primarily there for Roar. Motes with 20~ second duration are fine if the party is sitting in one area.
Eclipse from [Mirage] is another option is see frequently. Note that Eclipse only affects weapon damage, and not any abilities or status procs. You can certainly use Eclipse, but know that the second half of the ability, being more evasive and sturdier in dim lighting, is wasted. Being harder to detect doesn't matter at all when you can jump to be invisible.
If you're a fan of going even higher in Ability Strength, Empower is a fine option. Remember to activate Empower before anything else. The effect is additive and is not affected by things like [Energy Conversion]. It will always be a flat 50% bonus. I do strongly recommend having Empower subsumed on a single Configuration however. Specifically for use in the Index.
There's one final option, which I think is not something you should do, Gloom. Gloom already does everything [Wisp] does in her kit. You already provide massive healing and slow enemies with Shock Motes. It feels very redundant.
If you don't have Arcane Energize, I recommend using [Rage] or Hunter's Adrenaline for energy restoration. You can also craft Large Squad Energy Restores for yourself and allies if you don't want to spend a mod slot. You can run out of energy very quickly with 45%-105% efficiency variance and spamming Breach Surge. And reactivating Roar. Arcane Energize carries. Without it, you'll need additional sources of energy restoration. Another option is using the Exodia Brave Arcane to gain energy on Heavy Attack kills. I especially recommend this option if you choose to use Madurai for additional strength. Although, pairing Exodia Brave with Zenurik may alleviate the need to use [Rage] or Hunter's Adrenaline if you're trying to compensate for the loss of Arcane Energize. A final option is the Operator Arcane Energence Dissipate. When used to full effect, it's energy production is extremely high. Mix and match to your discretion to find what works for you.
Arcane Eruption is another option which, when paired with [Energy Generator], can be very fun. Without [Energy Generator] this Arcane is lackluster at best. But when you're spawning orbs constantly you can keep enemies locked in CC basically forever. It holds its own. If you're a fan of utilizing unconventional options pick one up off the market for cheap and try it out.
Use Molt [Vigor] for short missions like Capture, Spy, or Rescue. Alternatively, if you pair Emergence Dissipate, Exodia Brave, with [Energy Generator], you can opt to use Molt Augmented and Molt [Vigor] together.
Arcane Avenger is probably a better overall choice over Molt Augment so feel free to use that as well.
And there it is! Truly the best support build for [Wisp] in the game. Health, Speed, Crowd Control, Damage, and Energy support. It is possible to go much higher as well. This is the baseline. Crack a strength relic buff? Hello 1600+% strength with 480+/320+ Motes. Oh, you have a real [Nidus] on your team? Time to go MUCH higher. You can also benefit from other Growing Powers, Power Donations, or Equinoxs. I have had a 1700/1100 buff active before.
It's possible to hit 979% strength solo. To do so, you need [Amar's Hatred], Madurai for Sling Strength, [Power Drift], and Empower from the Helminth. But this is unnecessary, and you lose so much. No Roar, no duration (which matters less without Roar, but still), no [Primed Sure Footed], and no flex slot. I do not recommend this unless you're trying to meme.
If anyone can find ways to get higher strength solo without sacrificing anything, I'm happy to hear! Enjoy being completely unstoppable. ❤