The best Vex builds in Borderlands 4: Siren guide

The cynical and sarcastic Vex is not what you'd expect from a Siren in Borderlands 4. Instead of the phase grasp playstyle we've traditionally seen, Vex is actually more like the Beastmaster himself—FL4K—from Borderlands 3. While this new direction makes the best Vex builds in Borderlands 4 harder to pin down, she's got a lot more versatility thanks to it.

Below, I'll go over three of the best Vex builds you can make at max level, one for each of her unique skill trees, so you can make the most out of Borderlands 4's Siren. Of course, I'll also go over how these skills all come together with weapons, class mods, and other gear to reach their full potential.

Best Vex builds in Borderlands 4

Just like the other Borderlands 4 characters, Vex has three distinct skill trees that bring something new to the table, including an associated unique action skill:

Vexcalation: Master kill skills (even without killing enemies) and fire spectral blasts using the Incarnate action skill to focus solely on increasing Vex's power. You won't be using any minions in this build.The Fourth Seal: This skill tree focuses on Vex's reaper and spectre minions using the Dead Ringer action skill, similar to Zane's Double Agent tree from Borderlands 3. The idea is to make the most powerful summons for extra firepower, while also using them to further boost Vex's own offensive and defensive capabilities.Here Comes Trouble: Use Phase Phamiliar to summon your best bud Trouble to wreck face together, similar to FL4K's Beastmaster playstyle in Borderlands 3. With a focus on elemental damage and survivability, this tree is perfect if you're looking for a more laid-back approach, though it's certainly not as strong as the other two options.

Vex's trait is Phase Covenant: Vex is attuned to the elemental type of her current gun, converting all action skill and melee damage into that type (including kinetic damage).

Now onto three Vex builds, starting with what's generally her strongest setup, Vexcalation/Incarnate. I've listed the skills, augments, and captones in the order you'll want to pick them up, though remember that you can respec if you'd like to tweak things while levelling.

Vex build: Witchy Trigger Finger

(Image credit: Maxroll)Primary skill tree: VexcalationAction skill: IncarnateFavoured element: Kinetic

This build is all about dealing kinetic bleed damage (which is also considered a status effect) and using high critical hit chance to trigger Kill Skills without killing enemies, making it good for mobbing and bossing alike. Since Vex has access to so many powerful Kill Skills, it's easy to quickly buff yourself up before rinsing enemies with focus on weapons while weaving in Eldritch Blast.

To kick things off, you'll want to pick up Leeching Attunement, Bloodletter, and Material Components to power up your kinetic weapons. Together, these perks give you bonus lifesteal (which comes in handy later), reload speed, bonus kinetic and kinetic status effect damage, as well as the ability to trigger bleed on enemies.

These skills alone significantly improve your kinetic weapon damage, but they're supported by various Kill Skills to further boost your DPS, like Grave Sights and Grave Implements. Similarly, there's Drink Full, which causes your rate of fire to ramp up as you deal gun damage, and Blood is Power for bonus kinetic damage based on your lifesteal when your health is full, synergising with Leeching Attunement, Grave Vitality, and Essence Leech.

Then there's the Witchy Trigger Finger augment, which stacks to significantly increase gun damage and reloads your current weapon just for dealing damage with Eldritch Blast or Phase Explosion. Since we're using the Vibe Check capstone, which makes Eldritch Blast a charge skill and also doubles the cooldown reduction from weapon damage, it takes no time at all to get the ball rolling and keep the momentum.

Keep an eye out for class items that give bonus points to Grave Power, Grave Implements, and Grave Sights in the Incarnate tree, Enchantment from Phase Phamiliar, and Cold Iron, Portents of Suffering, or Grave Fiends from the Dead Ringer skill tree. These are valuable perks that we can't quite fully take advantage of with the current max level.

Here's where you should spend your skill points:

Vex build: Summoner

(Image credit: Maxroll)

This build centres around summoning multiple minions using the Dead Ringer action skill to boost Vex's damage output, while also benefiting from passive damage from the summons themselves.

The goal is to constantly have multiple minions on the field at once—gun-wielding reapers and scythe-slashing spectres—to deal bonus damage and apply status effects. Cold Iron and Fell Inscriptions boost gun and melee damage (plus max health) respectively, for both you and your minions. Obedient Fiends and Ancient Rites, meanwhile, provide blanket increases to minion damage.

Taking advantage of the Blood Sacrifice perk to trigger Kill Skills whenever a minion dies, you'll want to pick up just about every Kill Skill she has, particularly Grave Fiends and Grave Quickening. A point in Sanguine Fiends and Grave Assault is also handy, just since they'll be active so often.

This build also has a light focus on status effects, too, since your minions are attuned to your element. Portents of Suffering simply boosts status effect damage, while Prismatic Ichor makes it so that triggering a status applies another random element. From there, Cursed Blade and Extra Cursed let you and your Reaper minions curse enemies with melee damage, causing them to take kinetic status effect damage; Burning Attunement increases status chance when attuned to incendiary; the Wither augment deals status effect damage and causes enemies to take increased damage for a duration afterwards.

Here's where you should spend your skill points:

This build, in particular, has room for a few strong variations depending on where you'd like to focus. The build above uses both spectres and reapers to their full effect, though you could do one of the following:

Swap the Hellish Harvest augment with Coven, and solely use reapers to buff your own crit chance.Swap the Dark Pact capstone with Heirloom to give your spectres a copy of your gun and use the Coven augment for a gun-summoner build.Remove 13 points across Prismatic Ichor, Recurrence, Fell Inscriptions, and Grave Assault and put them in the following Incarnate perks for a more gun/bleed-focused build:Leeching Attunement (1/5)Grave Sights (4/5)Bloodletter (4/5)Grave Implements (1/5)Material Components (3/5)

Vex build: Here Comes Trouble

(Image credit: Maxroll)Primary skill tree: Here Comes TroubleAction skill: Phase PhamiliarFavoured element: Cryo (and ordnance damage more generally)

Do you find comfort in having a buddy by your side? Did you like FL4K, the Beastmaster, from Borderlands 3? Then this is the build for you, focusing on Vex's phase friend, Trouble, a cute (and deadly) spectral cat. While it's perfect for mobbing, since this build has some self-buffing potential even without Kill Skills, it should hold its own against bosses, too. I will warn you, though, Trouble's AI isn't too great, and this skill tree is significantly less potent right now compared to the other two options.

This is an ordnance build, first and foremost, with a focus on cryo damage, which'll also benefit Trouble because of Vex's attunement trait. Icy Attunement restores ordnance cooldown on kills while attuned to cryo, Claw and Bang boosts melee and ordnance damage for you and Trouble, and Blasted Fiends increases Vex's ordnance damage—a portion of which is also given to Trouble as minion damage. Trouble will also partially deal ordnance damage thanks to the Violent Outburst augment and Trouble Bubble capstone.

However, there's also quite a bit of survivability in this build, mainly with frequent overshields. The Overprotective Kill Skill grants both you and Trouble an overshield, while Blast Rites gives you an overshield and increased fire rate after activating your ordnance. These synergise with Corporeal to increase your damage dealt while you have an overshield, while also increasing maximum overshield capacity and duration.

Here's where you should spend your skill points:

If you'd rather not focus on ordnance damage, it's as simple as swapping from the Trouble Bubble branch to either of the other two. The Beast Mode augment and Unsealed capstone work well for its shock-focused branch, while Vorpal Fang and Double Trouble's branch is built around critical hits.

Nevertheless, I'd focus on getting points in Incarnate's various Kill Skill perks at the top of the tree, and Dead Ringer's minion perks going forward, whether that's through class mod bonuses or additional skill points from future level cap increases. It's rather annoying that the pet skills are split pretty evenly between Phase Phamiliar and Dead Ringer, as right now, you won't have enough points to fully beef up Trouble.