Vex’s Bloodletter build may just be the strongest build that Borderlands 4 will ever see. A seemingly simple interaction between a few of her Siren skills can quickly turn a Critical Hit into literally infinite damage. Furthermore, this incredibly high damage contained within this Bloodletter build comes with almost no caveats, killing almost any boss in a matter of seconds.
Vault Hunter Leveling Guides
In the event that you were looking for leveling guides for Borderlands 4 instead, please use one of the buttons below to quickly find what you’re looking for!
- Kills bosses in seconds.
- Work with any gear.
- Easy to play.
- Average at disposing groups of mobs.
- Enemies with immunity are tough to deal with.
Quick Navigation
Skill Trees and Playstyle
This Bloodletter Boss-killer build makes equal use of Vex’s Vexcalation and The Fourth Seal skill trees with an investment of 24 and 25 skill points respectively. Dead Ringer is the Action Skill of choice, taking advantage of the 25th skill point being invested into The Fourth Seal skill tree.
Skill Trees
The specific choices within the build revolve around targeting a small number of essential skills that are needed for the build to function, while the majority of skills simply provide the means to reach nodes deeper in the skill trees, providing some extra damage and consistency to support the key-pieces of the build as well.
Playstyle
The surface-level playstyle of this build is a simple one; score a Critical Hit with your gun to make Bloodletter create a damage-over-time effect that will increase in strength until your enemy dies. However, there are many small strategies you can employ to optimize how you play the build.
One of the most powerful tools you can utilize within this build is a Throwing Knife, specifically one with the Penetrator Augment effect, which will ensure all damage will be a Critical Hit for the next 5 seconds, including damage from Bloodletter itself. This will both increase your initial damage for Bloodletter to feed off of, and also allow its damage to ramp up much quicker. This massive acceleration of your damage is what allows this build to earn its Boss-Killer title.
Although it is known for using hard-hitting guns to take down titanic bosses, this build can make use of fast-firing weapons as well. Due to its ability to infinitely scale damage, it is possible to kill any opponent with any Critical Hit, no matter how small. With this in mind, you can also dispatch large groups of enemies by switching between targets once the damage from Bloodletter has been applied to a target. This process can be sped up even further by making use of Spectre minions to damage enemies as well.
Skill Breakdown
- Bloodletter—The build’s namesake and most essential skill to pick. The skill has a chance to apply a damage-over-time effect when critically hitting a target, based on the damage dealt. The DoT effect is also capable of being a Critical Hitt, stacking an additional DoT effect onto the target, and this build’s sole purpose is to take advantage of that interaction.
- Target Prescience—This skill provides a passive Critical Hit Chance to your guns. While the skill is technically optional, it provides a contingency plan against targets with hard-to-reach weak spots if you do not already have a 100% Critical Hit Chance against them.
- Keen Mind—Keen Mind is a much more crucial version of Target Prescience, providing Critical Hit Chance to your Skill Damage rather than your Gun Damage. This passive chance is one of multiple sources that allow your Bloodletter to critically hit itself, which allows it to refresh without you having to shoot the target again yourself.
- Keen Suffering—The damage caused by Bloodletter is both Status Effect Damage and Skill Damage. This allows Keen Suffering to further boost Bloodletter’s Critical Hit Chance alongside Keen Mind.
- Dead Ringer—Dead Ringer is the Action Skill of choice for this build. Unlike many other builds, the Action Skill is not that important in this build. That being said, the minions summoned do benefit from many of the Skill Damage boosts in this build, while their ability to draw the attention of enemies is never unwanted and provides additional survivability.
- Coven—The Coven Augment is the primary reason the Dead Ringer Action Skill is chosen for this build. Its ability to create on-demand Critical Hit Chance when summoning Spectres greatly helps improve the build’s consistency at delivering those crits you desperately want.
- Heirloom—Due to requiring skills deep into multiple trees, Heirloom is the only Capstone option for this build. However, the ability to create a Spectre equipped with a copy of your weapon, paired with some of the aforementioned skills, can really pack a punch.
Specializations
This Bloodletter build relies on Specializations more than any other. Similar to its skill trees, only one truly important Specialization exists, requiring 21 Specialization points, with everything else being built around it. However, to fully fill out your Passive Skill Tree, a total of 51 Specialization points is ideal.
The primary focus of the Specialization tree is to gain access to the Contamination passive. This passive further boosts the Critical Hit Chance of Bloodletter and, with the aid of the build’s skills, allows it to accumulate damage-over-time triggers faster than they tick down. It is at this point the build truly unlocks its ability to deal infinite damage.
In addition to Contamination, it is also advisable to invest into Daredevil if you have enough Specialization points, allowing you to pick up the I Am A Gun and A Honed Mind passives. These will significantly boost the damage output of your Spectre minions, pushing their damage potential even closer towards your own. This selection does not have much effect on your boss-killing potential, but will improve your damage output when fighting multiple enemies at once.
The last passive used by this build is In The Zone, allowing you to accelerate the rate at which you deal damage purely by aiming down the sights of your gun. However, the difference is very minor and this passive is merely the best passive option that is still available from a full 51-point allocation for this build. If you happen to have a lot more Specialization points available, you may freely pick from any other remaining passive.
Gear and Manufacturers
This build can flex its strength by being functional with literally any gear. However, by knowing what to look out for, you can significantly improve the effectiveness of the build.
Guns
When choosing guns for this build you should look for those with Kinetic damage. This allows for synergy with the Material Components and Leeching Attunement skills in addition to having more damage than their elemental counterparts. Jakobs guns are recommended to fill this role due to their high damage and lack of elemental affinity.
The role of your first gun is to deal a high amount of damage in a single shot. This, when paired with a Penetrator Augment Throwing Knife, allows you to deal the largest initial hit against bosses to dramatically speed up the effect of Bloodletter. For this you should look towards a high-powered Sniper Rifle, but a solid Jakobs Pistol will also suffice.
The aim of your second gun is to provide you with a way to take care of groups of enemies, allowing you to dish out Critical Hits to get your Bloodletter damage rolling. For this, high fire-rate weapons like Assault Rifles and SMGs are ideal and pairing them with the passive ricochet effect of Jakobs-manufactured weapons will further boost your ability to spread damage among the masses.
Due to your Ordnance slot being taken up by a Throwing Knife, you should look for an explosive gun as your third choice to provide you with a means to deal with Vile enemies. This can be achieved with the Noisy Cricket pistol. Its large splash area makes quick work of protective crystals.
For your final gun you can freely choose anything that you desire to use with the build. Some options include an alternative Pistol or Sniper Rifle alternative to your first gun, or a Shotgun for close-range combat.
Utilities
The most powerful utility item you can add to this Boss-killer build is undeniably a Throwing Knife Ordnance with the Penetrator Augment effect. Hitting a target with the knife will turn any damage they take into a Critical Hit for 5 seconds, allowing any amount of damage to ramp up into the millions due to Bloodletter. Despite the power of this effect, the build can still function without it, but unfortunately there is no alternative Ordnance available that synergizes with this build.
Thankfully this setup requires no specific Class Mod. You should prioritize finding a Class Mod with as many points into the Bloodletter, Keen Mind, and Keen Suffering skills as possible. As a bonus, you should also look out for Skill Critical Hit Chance, Skill Damage, and Status Effect Damage as secondary bonuses on your Class Mod
For your Enhancement, prioritize using one with bonuses to Jakobs-licensed parts due to how well most Jakobs weapons work with this build. Enhancements with the Piercer effect, to increase your passive Critical Hit Chance, or Leaper effect to give you a passive ricochet chance, are the best options available. This can be further optimized by looking for secondary bonuses providing Damage or Critical Hit Damage.
Your choice of Repkit within the build allows for much more personal preference. The most optimal Repkit trait to look for is the Amp effect, providing you a 200% damage bonus to your next shot and is perfect for taking down bosses. However, due to the build having so much damage already, you may prefer to choose defensive effects like Overshield or Power Cycle to provide you with some immediate shielding.
There are no noteworthy Shields for you to look out for with this build. Instead, you can simply pick the best shield you have available based on its capacity and regeneration rate.
Firmware
Deadeye is the core Firmware set used by this build. Its synergy with Critical Hits feeds directly into the build and your priority should be to get the full 3-piece bonus before anything else.
For the remaining two Firmware slots you may freely choose between gaining more Critical Damage from Trickshot, Badass Damage and Damage Reduction from God Killer, or Action Skill buffs from GOOJFC.
Quick Tips
- Use a second Throwing Knife to reapply the Penetrator Augment to speed up boss kills.
- Use your highest-damage-per-shot weapon when applying Bloodletter to bosses.
- Make use of your minions to spread Bloodletter amongst many targets.
