You don't have to Umbra Forma for [Umbral Intensify], [Intensify] works fine as well

Hey all, LuxianGonff here,
This is a [Caliban] build that I have made over a long time of playing him and experimenting with all kinds of different builds, subsumed abilities, weapons, and companions. The most important thing to note about Caliban and what his playstyle is like, is adaptability. At surface value, Caliban seems to be a 'watered-down'/weaker version of other frames, with a weird summon that doesn't seem to do much of anything. Experimentation is exactly where [Caliban] shines, as he works in many different ways, with many different allies (Warframes, Companions, Specters, Defense objectives, and other allied Summons), and especially as a soloist.

Recent Updates
The main update to this build recently is the change to [Primed Redirection], which granted a much larger Shield pool to work with. It just made this build that amount of Shields tankier, and helps your Companions stay alive if you use Link Redirection on them.

Overview/Abilities:

In general, Caliban is a support and crowd control-oriented frame, having a fairly decent amount of CC from just a couple abilities, while also amplifying the amount of damage that enemies take with your 2 ability having percentage Damage Vulnerability, and his 4 ability being a full armor/shield strip. His passive, though it is a significantly weaker version of [Adaptation] that also has less conditions to be able to build the damage resistance than [Adaptation] does, it is still a passive of 50% [Adaptation], nonetheless. Treat it as though it exists, and nothing more. It activates, it applies to all allies in your affinity range, and in long endurance missions especially, your team is likely to not be using [Adaptation], so it can still help, even though it is quite weak in comparison to [Adaptation].

Your 1st ability, Razor [Gyre], is pretty much only there to be subsumed out, as its damage is pitiful, and you are very vulnerable to just dying while you're locked into this spinning animation. Because it is easily subsumable, it allows [Caliban] to mix actually good abilities into his kit, to pair with his other three abilities, all of which are very strong in their own right.

Your 2nd ability, Sentient Wrath, is an extremely useful ability, as it allows [Caliban] to slow the pace of incoming enemies, single out Eximus units from the rest of the crowd, and apply % damage vulnerability to every enemy that it hits, while lifting all enemies that don't have Overguard. Keep in mind that if you want 100% damage vulnerability from Sentient Wrath, you need to have 287% Ability Strength, which is attainable with any number of combinations of Flex Mods/Arcanes below. I understand that spamming lifts can be annoying to a fair amount of players, and you really don't have to cast it all that many times for it to be effective, so be wary of that. The ability has a sort of internal cooldown, as it won't allow you to recast it while it is still expanding to its maximum range. That brings us to the range aspect of this build: you don't need a lot of range to be effective with these abilities. The 2, especially, has a naturally high range, and it scales with the range stat highly as well, so you don't need much range at all. If you are soloing, spam this all you like, in fact, it's encouraged, as it helps with survival as well as being able to clear higher level enemies the further you go in Steel Path endurance runs.

Your 3rd ability, Lethal Progeny, is the true calling card of [Caliban]. This allows you to summon three Conculysts to fight for you, all of which have a very high threat level, so they take a lot more aggro than you. These guys combo extremely well in the front line with Companions ever since the Companion rework. This also makes [Caliban] a great user of MOST types of weapons, allowing him to be a great weapon platform frame. You can use longer ranged weapons and have your Conculysts be your front line as you pick out enemies from the crowd or jump into the fray alongside them, spreading maximum Statuses and CHAOS. One of the greatest things that Conculysts offer back to [Caliban] is very high amounts of shield regeneration. Any form of shield return, such as [Brief Respite], Augur set mods, or other sources such as Warframe abilities, will cause your Conculysts to rapidly regenerate your shields up to a certain level of Overshields, making Shield Gating very simple on him as long as you slot any of these things into your build. The amount of shields regenerated per second is based on your Ability Strength, giving more reason to have high Strength. The Conculysts' level also scales with your Strength, and the level of your Conculysts is where a bit of the build trap lies with Caliban. You only really need to have Conculysts that are level 75-105, as these guys don't exactly do a large amount of damage based on anything to be honest, but you want them to be around that level for the health pool they will have around those levels. On top of all of this, your Conculysts also have Sentient [Adaptation], so they are actually insanely tanky, making them be ideal for being the aggro tanks that they are.

Your 4th ability, Fusion Strike, is an incredibly good armor/shield strip, as it allows you to directly pick the exact areas you want to be stripped, as well as it resides on the floor for a decent amount of time after the initial explosion. The explosion will Knockdown enemies, pulling them toward the center of the blast by a slight amount, meaning it can be a useful tool to crowd control enemies as well. Leaving these zones in certain doorways or tunnels is extremely useful, as enemies will essentially armor/shield strip themselves, much like [Xaku]'s [Gaze]. Casting Speed on Archon Shards is necessary, however, as this ability has a pretty hefty casting animation. Keep in mind that the explosion zone resides there for a while, and you can set down several at a time, so you can create a line of defense, covering multiple approaches. The energy cost is quite large as well for [Caliban] not having a very large Energy pool, but Nourish helps so much with all of his energy problems. The biggest downside to this ability is this stupid bug that DE hasn't fixed since his release, where you can't see the residual fallout zone of your 4th ability, making it hard to gauge where your armor/shield strip zones are at, and where they [Reach]. Unfortunately, there seems to be no alleviation to this, just certain conditions, such as areas you are in, causing it to actually be visible (very rarely).

Shield Gating/Survival

Use any of your available skills to reset your shield gate. They should all get you to a solid amount of shields, your 3 being the best, as you can spam it 3 times rapidly, and the 4 will always fully reset your Shield Gate instantly. The most consistent ability combo for Shield Gating are your 1 and 2 abilities. Your Conculysts fill in the remaining shields fast enough to reset your shield gate as long as you dont wait until the last second of your Shield Gate invulnerability. [Rolling Guard] works well with Shield Gating as it would in any other build. [Redirection]+[Fast Deflection] along with the new Shield Gating changes that were made recently make his survival extremely easy, and very consistent. It is so much easier to survive on him now.

Abyss of [Dagath] Shield Gating Update
Abyss of [Dagath] came with so many good changes for [Caliban], and particularly helpful with this build, allowing Companions, who are much better and no longer a liability, to have a very wide access of Elements/Statuses to spread in an AoE. Shield Gating was also changed to have a certain threshold that you must meet in order to reset it, instead of filling the entire shield up in order for it to reset. On top of that, the invulnerability period you get from your Shield Gate now scales with Max Shields, so [Redirection] now has an incredible usage on [Caliban]. You also aren't forced to use a Decaying Dragon Key to have any bit of reliability for resetting your Shield Gate. All in all, Abyss of [Dagath] was a very good update for [Caliban], and a great step in the right direction for him in the future. Now let's hope we finally get any bit of updates or augments for him...

Mods/The Build in general:

You no longer have to use a Decaying Dragon Key for survival, as per the Shield Gating changes from Abyss of [Dagath]! This has helped change [Caliban]'s build up a lot to make his survival more consistent.

This brings us to the use of [Redirection] paired with [Rolling Guard]. [Redirection], ever since the Abyss of [Dagath] update, is much more useful for frames with high shield pools, as the invulnerability time period when your shield breaks scales with your Max Shields, capping at 1200, which provides a 2.5 second invulnerability period. This along with [Rolling Guard] makes you incredibly hard to bring down on [Caliban] now, especially when paired with [Brief Respite], Augur Set mods, and other forms of Shield Return. This also makes [Redirection] a great pairing with [Fast Deflection], as your 2.5 seconds of invuln will be almost all the time that you need to start regenerating your shield from the point of it being broken. A quick [Rolling Guard] or cast of any ability will easily bridge any gaps in invulnerability frames, and the rapid regeneration given from [Fast Deflection] paired with your Conculysts' shield [Regen] will make you exceptionally hard to bring down. These new changes from Abyss of [Dagath] helped [Caliban] a lot with survival!

While [Blind Rage] is a must for this build's Strength, you do have some flexibility in what stats you need after that. I recommend Intensify/[Umbral Intensify]. The extra strength you will get will serve to the multiplier on extra energy gained from Nourish, allowing for a much easier and more streamlined means of sustaining energy, not even needing Zenurik Focus tree to maintain your energy realistically. This will open up your choices on Focus trees that you would rather use instead of being locked to Zenurik for energy (every Focus school works well on [Caliban] in one way or another). Strength will also make the percentage of Viral damage higher, making it closer to being an almost equal Viral damage percentage to a mix of a Primed Cold mod and a Status Toxin (165%+60%=225%) mod mix. Emergence Dissipate on your operator mixed with Nourish also pairs extremely well for this build.

Nourish has a 'thorns/retaliation' effect on it, so when you get hit, you do a pulse of Viral damage in a circular AoE around you, as well as doing direct Viral damage to the attackers (with a guaranteed status proc on both). This applies to Conculysts with Nourish as well, which have a high threat level, meaning they get attacked a LOT. This maximizes your amount of Viral spread without having to put yourself into danger by taking the damage. You must always wait to cast Nourish after summoning your Conculysts to give it to them as well.

Nourish with this level of Strength allows for you to quite freely modify any of your weapons as you see fit, allowing for more flexibility on elements you want to build, or even compress some mods in order to access higher damage with the reliance on a full amount of Viral damage as if you had it modded on any of your weapons. This works extremely well on higher status weapons that you would like to get extra usage from Condition Overload and Galvanized Aptitude/Shot/Savvy.

Flex Mods/Arcanes in this build:
-Primed Sure Footed <-> Handspring
-[Fast Deflection] (this mod is incredibly good for Caliban's survival since the Abyss of Dagath shield gating changes, especially paired with Arcane Aegis)
-[Brief Respite] (this is a much more reliable source for shield gating, usually will only take one cast of any ability to fully reset your Shield Gate)
-Stretch (usually swapped for Augur Reach if you are needing more Shield return, or aren't using Brief Respite)
-*Arcane Aegis (much more useful since Abyss of [Dagath], pairs extremely well with his Conculyst shield regeneration, and Fast Deflection if you choose to pair these together)

Alternate options for these:
-Growing Power (pairs well with both Zenurik and Madurai for extra boosted Nourish and Conculyst levels)
-Combat Discipline (keep it as low level as you possibly can, you don't want to hit yourself for 10 damage every kill)
-[Mecha Empowered] and [Mecha Pulse] (with a Predasite of your choosing that has both Mecha mods in its build to maximize usage and range for the Mecha set bonus. Highly recommended you try this build out for yourself)
-[Mecha Pulse] (using just [Mecha Pulse] without Mecha Empowered is still very viable with a Predasite, you are missing out on a 15 sec lower cooldown without all 4 set mods though)
-[Augur Secrets] (more Strength is always good on Caliban, this helps reach 287% Strength for the 100% damage vulnerability on Sentient Wrath)
-Equilibrium (usually want to combo this with Combat Discipline and a Companion that has Synth Deconstruct)
-Arcane Avenger (pairs very well with Combat Discipline, Nourish, and most weapons)
-Molt Augmented (usually the easiest to reach the 287% Strength for Sentient Wrath, and provides a higher Conculyst level)
-[Augur Reach] (works particularly well if you are not using [Brief Respite], as it's a good supplement for Shield return)
Most aura mods work well for [Caliban], so you can mix and match on that how you please

Synergy with Companions:

With all of this high amount of access to Viral on all of your weapons with Nourish, as well as the consistent AoE spread of viral from your Conculysts being damaged by enemies, you essentially take the role of a Panzer Vulpaphylla for spreading Viral for you and your team. This also opens you up to having more options in terms of companions. Sentinels, Hounds, Predasites, Kavats, and even MOAs work excessively well on this build with the proper builds and the proper attention paid to them during gameplay.

Hounds surprise me on how insanely strong they are with this build. They are an excellent choice for most players who have access to hunting Sisters of Parvos, as they are earned simultaneously with hunting said Sister. They have long been understood to be relatively weak or just not as effective as other choices for Companions, but Abyss of [Dagath] changed a LOT in their favor. Survivability has been severely improved on pretty much all Companions. As well, Hounds have ridiculous access to status spreading in a very large AoE from [Manifold Bond], [Contagious Bond], and the Hound Precept mods [Repo Audit], [Synergized Prospectus], and [Reflex Denial]. Hounds on this build will grant them access to Viral from Nourish, so mod their weapon accordingly to maximize unique statuses!!!

Predasites have very good synergy with this build, having access to the Mecha set mod, which is incredibly powerful when used correctly. The Mecha set bonus works incredibly well with this build, and most weapons that have good statuses. To round this all out, your Conculysts having high threat level draws a decent amount of attention away from your companions, helping them survive longer, also synergizing well with this build.

Focus Schools:
Every Focus School has a usage on [Caliban] in one way or another, it all depends on what you want to use, and Nourish opens up your options to anything.

Zenurik has its obvious uses for Caliban as it is useful to any other frame that is energy-hungry with their abilities. One core usage for Zenurik on [Caliban] is being able to cast all 3 Conculysts while you're in the range of your Hardened Wellspring, allowing for a nice little bonus in some extra levels for the Conculysts, and reaching closer to that 225% Viral elemental mix. With Nourish, you will most definitely never have energy problems while under the effects of Wellspring.

Vazarin is exceptionally good on Caiban, firstly, by granting additional Affinity range for your passive to [Reach] further (not extremely useful, but must be noted, nonetheless). Secondly, and much more importantly, it grants him additional access to Shield Regeneration from your 1st Operator/Drifter ability. This allows for incredibly good synergy with his Conculysts and it allows him to not have to worry so much about his shield gating, and can play more offensive in doing so. The survivability granted with Vazarin is also in the extra little bit of CC that it provides with its 2nd ability, an 8m vortex that is relatively low cost and very functional in many ways, splitting the battlefield, or just disrupting an entire doorway/tunnel of enemies. Lastly, your Void Sling/Dash is absurdly useful, to not only [Caliban], but also his Conculysts, his allied Warframes, and very importantly, his Companion. Being able to make an ally invulnerable for 4 seconds as well as healing them rapidly is nothing to look down upon, that is effective in many ways, especially in keeping an important Hound or Predasite alive, the latter of which is allowing your Mecha set to flourish, or prevent your Conculysts from taking a high amount of damage during a longer endurance run. The flexibility this Focus tree offers for [Caliban] is incredible, and I highly recommend at least giving it a try.

Madurai is also a very strong and useful tree for [Caliban], as it would be for many other frames that would use Madurai. The bonus physical damage is always nice for many different types of weapons, and of course, the access to 40% Ability Strength and 50% Casting Speed. Needless to say, Madurai is a very useful choice as well, and easier to sustain when you have Nourish to rely on for Energy. This is a really good pick if you are looking for those higher level Conculysts and that higher percentage Nourish in order to [Reach] the 225% Viral elemental mix, as if you time it correctly, you can really get the most out of that extra 40% Ability Strength and 50% Casting Speed with [Caliban].

Naramon is quite the underrated pick here, but it is actually seemingly incredible on [Caliban]. With his easy access to the Lifted status, proccing Lethal Levitation is extremely easy, making this a great Focus school to take if you really want [Caliban] to shine as a weapon platform, which he can do excessively well (particularly in melee). It is recommended you have some sort of AoE firing mode on your Operator/Drifter's amp, as this makes Lethal Levitation procs even easier. This also allows for an interesting 'form-swapping' style if you so choose to play it, swapping between Warframe and Operator, constantly benefitting each form by doing so, while also still having your area of influence from your Conculysts with Nourish still being out and attacking while in Operator form. If you would like to further expand on the Lifted status access, using an Impact melee weapon with the Saxum Set bonus is quite an effective option.

Unairu is yet another effective pick for this build, with Stone Skin providing a nice little chunk of Armor for you. Though you already have access to armor/shield strip, both Caustic Strike and Magnetic Flare can still help to ease your Energy costs from using 4 as much. Wisps are also a great plus, also opening this Focus school pick to work similar to the idea of the Naramon school above, in a 'form-swapping' style that you may find fun (you don't have to do this, obviously). And of course, Last Gasp and Vengeance are excellent, particularly so when playing solo.

'Necessary' Archon Shards:
2 Amber Shards - Casting Speed (regular or Tauforged works)

The other 3 Shards are flexible into what you want out of this build:
Crimson Shard - Ability Strength/Duration (The weapon stat buffs from Crimson can work if you prefer those as well)
Azure Shard - Max Energy/Health
Amber Shard - Effectiveness on Energy Orbs
NEW
Emerald Shard - Max Corrosive stacks, as you will mostly be modding Corrosive damage on your weapons and Companions
Topaz Shard - Regenerate Shields when you apply Blast status (combos well with your Conculysts to keep your Shields always regenerating while building your Adaptation passive)
Violet Shard - Primary Electricity damage, Melee Critical Damage if Energy is 500+, and Health/Energy Pickups Conversion (all of these work really well, the Health/Energy Pickup Conversion being best when combo'd with [Combat Discipline])

This build's greatest suit is its ability to open up the true versatility that [Caliban] offers, while also still sticking to what is effective at almost all levels of play, including high endurance Steel Path. All of these abilities don't require a large amount of range to be effective, leaving you open to build a high amount of Strength without the [Overextended] tradeoff. His ability to be an offensive support for himself, his allied Tenno, his Conculysts, Companions, and even Specters and Kahl's Squad, is incredible, while also being a very fun frame to play, as you sort of feel like a miniature army that can cover a lot of ground. Since the Abyss of [Dagath] update, Nourish [Caliban] paired with a Hound is incredible at spreading statuses in a large area of influence, and no longer feels like you are barely surviving until your next [Rolling Guard] is off of cooldown.