[Build] The infinity - A purple tree pilot build

The infinity (but it’s actually just a long-lasting Iron Bear)

Fuel crisis what?

Do you enjoy piloting Iron Bear so much you wish it would never end, as its duration would be almost …infinite? This is a pilot build that offers no regard for Moze’s safety outside IB but handles pretty easily any endgame content: you will clear both true MTD and GTD with little effort.
The gimmick of this build is - predictably - extended Iron Bear uptime! However, I sacrificed some of the theoretical maximal uptime to achieve more damage and make the build gimmicky but viable. Fear not, you will still experience up to five minutes of Iron Bear duration (in certain areas).

Skill Tree


This build was designed to heavily rely on the new purple tree, Mother Bear, to create a build that is 1) tanky 2) free from the shackles of vampyr 3) offers a good deal of damage thanks to the addition of a Raging Bear com, that offers both fuel efficiency and damage the more you fight.
The loop here is pretty simple: Raging Bear offers both fuel efficiency and damage, while the Mother Bear tree offers healing via Biofuel , additional fuel and fuel refund via Nitrotrinadium Engines, and Never Gonna Give you up. Combined with the various bonuses on status effect and status effect damage, the more you fight the more damage and healing you get, and the more fuel you obtain to keep killing everything!

Class Mod

The ideal roll are + 3 on Deadlines for increased fuel capacity, and 2+ on Stainless Steel Bear to boost our health and damage and yet more fuel!
AS damage is a must-have passive roll, the other two can be whatever.


Victory Rush, with a Snowdrift prefix; nice QoL when in a pinch or you have to move outside Iron Bear and mobility can come in handy.


Multivitamin prefix, and 75% extra health upon exiting Iron Bear anointment? And you can exploit it? Is this the sound of a 5.8 mln HP walking disaster that I hear?


You don’t really need weapons here, Iron Bear packs a punch for the both of you, but why not help it in its path of destruction?

Any weapon would be viable here, as long as it bears the right anointment. Extra damage for my railguns? Heck yeah!

Additionally, you can use anything you want as a second wind weapon, if you happen to be downed outside IB. A Plasma Coil or a Backburner work wonders here, I speak from experience.


This is honestly just for QoL. Applying rad DOTs will help you to dispose of enemies and possibly chain kills. A cryo version also works wonders if you want more crowd control. I’ve had positive experiences with both.

Additional equipment

This build requires a bit of micromanagement, especially in deciding when to keep pushing and fighting, and when to dismount Iron Bear and wait for your action skill to cool down. But what if you are impatient or in a pinch? Don’t worry, I got you covered!
This is a totally optional step, but you can equip a random low-level Sellout and set yourself ablaze. Why would you do that, you ask? Because you can com-swap to an Eternal Flame, ignite yourself and immediately reset your AS cooldown! Then, get back your Raging Bear, re-equip your Infinity and go back to Iron Bear!

Finally, you can see here the build in action

Special thanks to Mad Glenny that helped me brainstorming the build, and the guys at the Borderlands Retirement Village discord server!

Click Here For the Build Template used for this post


I read (in the Iron Bear Compendium) that the drones created by the Dark Army are still active when piloting Iron Bear. I’m not sure how effective they are but they can provide some extra damage along with the grenades while powering up Iron Bear with an anointment.

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Oh, I wasn’t aware of this! That is definitely a nice thing that I will test tomorrow to see its impact!

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Try this with the cryo miniguns and watch as you freeze everything in 1-2 shots. It’s beautiful

Have you tried this with Dakka bear and mounted the turret while equipped with a trick unforgiven that has the 432% crit bonus and either the Urad or 300/90 annointment? Since the turret adopts both the crit bonus and annointment I would be interested to see how it performs.
An action skill cooldown rate roll sounds like it will also help. If you’re on PS4 I have a raging bear with both AS damage and AS cooldown rate on them, level 60 though. I can give you the 300/90 unforgiven too if you like.

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I specced dakka for the damage bonus but as you can see there is no auto bear specced on DM. I tried a couple of variations with this build, for example speccing the purple capstone “running on fumes” by sacrificing one point on SSB. Believe it or not, it makes a huge difference in terms of fuel availability, so I left it as it is.

Likely I can take one point out of the MB tree and spec autobear to have these 15 seconds of immunity phase when AB expires in less than ideal scenarios, but I haven’t tested completely the impact of the last two purple specced skills to be certain that is a good idea.

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I like that you went for a non-splash build with the railguns, it allows the Bear Mother tree to have more skill points and more time in the spotlight in this context without trying to go for Corrosive Sabot Round, Torgue Cross-Promotion and Vampyr.

After watching the vid, I wasn’t really seeing how Superior Firepower was making much of an impact. All the trash mobs were dying to single railgun shots and the meatier enemies such as the bosses were mostly wearing armour anyway so any non-corrosive DOTs were just tickling them. I would say take the skill point from that and put it into Auto Bear - it would allow you to make use of Dakka Bear and then you’ve got yourself a 100% pilot build!

EDIT: theoretically speaking, would you not be better off taking a point out of Nitrotrinadium Engines and allocating it to Running on Fumes? 5% of the base fuel tank capacity is worth 6 seconds which you can break even with the capstone just with one ignition alone, not to mention how much time you’d save with multiple ignitions.

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This is an excellent point. As I stated earlier I still need to test properly all the skills from MB and if Superior Firepower doesn’t cut it I will gladly move that point to AB.
It would definitely help with the shortcomings of this build, so I’ll test this change asap and eventually update the skill tree.

As for Running on Fumes, well…
At the moment ROF prevents only idle fuel consumption. Honestly, it looks like a very meaningless addiction for a tree and a build that gives you back fuel all the time. Idle fuel consumption is the last of my problems here, so I decided to not spec it for now.
I sent a ticket to GBX illustrating how this capstone does not affect at all IB/IC fuel consumption. I am waiting for them to hear if this is working as intended or not.

Hmm it’s an interesting build for sure but you’re just missing so much potential damage using this class mod. I made a build myself using purple, blue, green tree and just slamming on blast master. Dual rockets just melts wotan in +/- 30 seconds. Even with blast master I can stay in IB a long time.

As long as you spec into deadlines you mean, right?

Raging bear helps with uptime, the gimmick of the build, but also don’t forget that while a burst of VP might be more powerful in single targets scenarios (and a single rocket does a quarter of damage of a single railgun shot, 505k per rocket vs 1.82 million per laser, mind that) cap arm offers more crowd control because it splinters, and each splinter does 1.3 mln damage. I am not missing that much out, if any, believe me.

I think it depends on what the build is aiming for. I bet you are even losing more damage if you use Eternal Flame than Raging Bear or Blast Master. But IB is too OP that it looks like any class mod or none at all will work.

Between RB or BM, if your goal is long uptimes, RB wins. If the goal is being able to kill mobs and bosses, either com is viable.

I think the new anointments for Iron Bear are doing far more than anything else the new content has brought - double Railgun damage on my Bear build is making everything on the true takedowns pop like balloons, and that’s just when rolling with the Bear Trooper COM. Each critical hit can be doing hundreds of millions of damage. It feels like playing Salvador in BL2 all over again.

I hear you, it straights up doubles IB’s weapon damage.
On one hand, it opens to the use of underperforming augments (hopefully you saw the build Kabflash posted earlier) like salamander. On the other hand, we are in front of a classic GBX carpet buff that yes, improves all weapons, but the pre-existing gap between a salamander and a railgun still exists, even if now both can be used.

I’ve found flare or minesweeper to be the best option; even running hammerdown protocol (same skill trees except without 9 orange points to get to it) I’m able to get through the first round of SS with a single ib activation without an issue, so the extension mods just feel like overkill at this point.

Also if you want to feel like a god without having to put in any effort, i highly recommend the hammerdown spec (with 1 hammerdown and 1 vanquisher for takedowns). Personally i find it boring, but if you’re into “look in that general direction, push button, all die”, it’s the setup for you

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My take on your build

All of your gear and such is good I just question some of your skill choices. This should maximize bear damage and survivability while also leaving all the uptime. It’ll also make Moze a bit better on foot.

A few considerations:

  • Harmonious Havoc is bugged. There are several instances where you will lose your bonus for no reason. For the state the skill is now it’s just a waste of points.
  • Grizzled: again, waste of points. If you find outside of IB 10 seconds of topped off are enough to set you back on track. Flame-swap with a sellout or a Musket work even better because you don’t have to damage yourself.
  • The entire red points distribution: puzzling. You lost DiB, that lone doesn’t make Moze better on foot, but most importantly you lost a lot of power on IB in the for of Capacitive Armature without really gaining much for Moze.

Also, I see where you are coming from but this is a pilot build. Exclusively. There is no Moze on foot. The build is not designed to aid Moze in any way whatsoever, it’s everything about IB.
Moze will never be on foot in this setup unless she has to go to the bathroom. I could have gone with no gear at all if not for the new anoints that “forced” me to go with something to boost IB hardpoints, and it would have worked fantastically still.

The only change I’d make to the skill tree would be to move the point on fired up to big surplus, just in the unfortunate case IB breaks and you can’t use dakka to give yourself safety while cooldown gets IB back

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Has anyone tried to set the record for time in cockpit? I’m wondering how long you could go on a single ride.

I stayed in four four rounds of slaughter star 3000. But that was less about longevity and more about time to kill and ability to spread damage effectively.

  • yeah HH is just there really to move down the tree, you need 5 and it has 5 that’s why I picked it. when it’s not bugged I think it’ll be a good choice. You can put those point in any of the surrounding skills if you like, none of them help bear much.

  • I entirely disagree about grizzled, I know you stay in bear a 90% of the time but accidents happen and sometimes bear explodes. In that situation you’re going to want to get back in bear as quickly as possible and grizzled is the best way to do that.

  • by not investing in the red tree I picked up TCP which increases splash damage, which with the right weapon is IB damage and grizzled which I already explained. So you’d invest in red just for capacitive armature? You need two rail guns to get the specialist bear so you run two CA’s? Or Hell on rails and CA? That’s not the best weapon combination IMO, if you were going all the way to sabots I could understand but I don’t think its worth the investment just for Capacitive armature.