Vex had a rough upbringing that was made more complicated by receiving her Siren powers. Her cynical and sarcastic demeanor comes from having to fend for herself and scrape for everything she's got. But underneath her salty exterior, Vex is an empath who knows better than anyone how much life can suck. Ever the pessimist, Vex still believes in helping others. And if helping others means dealing damage to oppressive jerks, Vex will always be first in line.
She wields supernatural phase energy to devastating effect. Vex can use that energy to empower herself, or channel it to conjure deadly minions that fight alongside her.
VAULT HUNTER BASICS
Three distinct Action Skills are available to each Vault Hunter, but only one can be equipped at a time. Note that some items in the skill tree (Augments and Capstones) must be equipped into your loadout to gain their effects.
Every Vault Hunter has three skill trees, each stemming from an Action Skill. You'll need to invest five of the Skill Points you get from leveling up into a given row to unlock access to the next row. Once you've invested 15 total Skill Points into a skill tree, you'll have access to three Branches for that skill tree; at the bottom of those Branches is a powerful Capstone (more on those in a moment).
Augments are enhancements that provide secondary bonuses to your Action Skills. In most cases, only one Augment is equippable at a time.
Capstones are powerful enhancements that modify or override specific Action Skill functionalities. A Capstone can be found at the bottom of each branch of a Vault Hunter's Skill Tree. Only one Capstone is equippable at a time.
You can use Action Skills from other skill trees even if you haven't invested any points into them, but you won't be able to equip the powerful Augments or Capstones from one skill tree onto the Action Skill of a different skill tree. Committing Skill Points to the skill tree that will properly synergize with your favorite Action Skill is key!
Note that all skill names, descriptions, and numbers listed below are subject to change; Vault Hunters aren't exactly known for being predictable.
Vex Abilities Breakdown
SIREN VAULT HUNTER TRAIT
Phase Covenant
Vex is Attuned to the Elemental Type of her current Gun, Converting all Action Skill and Melee Damage into that type.
SIREN ACTION SKILLS

DEAD RINGER
(The Fourth Seal skill tree)
Charge Skill (3). Spawn a Phase Clone Minion, choosing Specter or Reaper. Phase Clones lose an ever-increasing amount of Health per second, and their Damage Type matches Vex's current Attunement when spawned.
Can spawn a Reaper that Taunts enemies and deals Melee Attack Damage, or a Specter that deals Gun Damage and cannot move.
SIREN SKILL TREES
The Fourth Seal



Sanguine Fiends
5 points
Kill Skill. Vex and her Minion(s) restore Health.

Idle Hands
3 points
Vex and her Minion(s) gain Reload Speed based on the fullness of her Health.

Cold Iron
5 points
Vex and her Minion(s) gain increased Gun Damage.

Fell Inscriptions
5 points
Vex and her Minion(s) gain increased Melee Damage and Maximum Health Capacity.

Grave Assault
5 points
Kill Skill. Vex and her Minion(s) gain increased Fire Rate for a Duration.
This effect can stack.

Ghast Blaster
Minion Skill. Specters gain the ability to use Ghast Blast, dealing Gun Damage to all nearby enemies on impact.
Specters will use Ghast Blast on spawn, and after they Reload.

Portents of Suffering
5 points
Vex and her Minion(s) gain increased Status Effect Damage.

Coven
Spawning a Reaper grants Vex and her Minion(s) Health Regeneration for a Duration.
Spawning a Specter grants Vex and her Minion(s) Critical Hit Chance for a Duration.
Both effects can stack.

Cursed Blade
5 points
Vex's Melee Attacks apply Curse to hit enemies, making them take Kinetic Status Effect Damage any time they take Gun Damage.

Blood Sacrifice
1 point
Activate Kill Skills whenever Vex's Minion(s) die.

Grave Fiends
5 points
Kill Skill. Vex and her Minion(s) deal increased Damage.
This effect can stack.

Grave Quickening
5 points
Kill Skill. Vex gains increased Action Skill Cooldown Rate.
This effect can stack.

Extra Cursed
1 point
Curse Damage now triggers on Minion Melee Damage, and deals increased Damage when it's triggered by a Critical Hit.

Blight Attunement
5 points
Attunement Kill Skill. While Vex is Attuned to Corrosive, killing an enemy creates a Haunting Remnant Minion for a Duration that seeks our nearby enemies, dealing Corrosive Status Effect Damage over time.
Kill Skill. Restore Haunting Remnant's Duration, if active.

Wither
5 points
Attunement Kill Skill. While Vex is Attuned to Corrosive, killing an enemy creates a Haunting Remnant Minion for a Duration that seeks our nearby enemies, dealing Corrosive Status Effect Damage over time.
Kill Skill. Restore Haunting Remnant's Duration, if active.

Prismatic Ichor
5 points
When Vex or her Minion(s) apply a Status Effect, apply another random Elemental Status Effect.

Keen Suffering
5 points
Status Effect Damage gains a chance to Critically Hit.

Ghasterbait
3 points
Whenever Vex Dodges, she creates a Specter nearby and becomes Invisible for a Duration, or until her next Gun Shot.

Shot to Go!
3 points
When Vex swaps her current Gun, her new Gun has its Ammo partially Refilled.

Necrosis
5 points
Vex gains increased Corrosive Damage and Corrosive Status Effect Damage.

Heirloom
Specters gain a copy of Vex's currently-equipped Gun for a Duration.
Only one Specter can have a copied Gun at a time, and spawning a new Specter will remove the copied Gun from the previous Specter.

Burning Attunement
5 points
Attunement Skill. While Vex is Attuned to Incendiary, Vex and her Minion(s) gain increased Critical Hit Damage and Status Effect Application Chance.
These effects persist for a Duration after Attunement is switched.

Hellish Harvest
Minion Skill. Reapers gain the ability to use Hellish Harvest, dealing Melee Damage 3 times in a large area around themselves and regenerate Health for each enemy hit.
Reapers will use Hellish Harvest on spawn, and every third time they Melee Attack.

Recurrence
Whenever Vex deals Gun Damage or Melee Damage, gain a Stack of Recurrence, which increases her and her Minions' Gun Damage and Melee Damage.
Stacks of Recurrence are lost if a new Stack has not been gained for a Duration.
This effect can stack.

Reverburnations
5 points
Melee Damage dealt by Vex or her Minion(s) has a chance to deal Incendiary Melee Damage.

Haruspex
5 points
Melee Override. Vex now throws a Phase Dagger from her offhand that deals Melee Damage to enemies hit. Phase Daggers can Critically Hit.
Kill Skill. Haruspex's Cooldown is reset.

Burnt Offering
5 points
Vex gains increased Incendiary Damage and Incendiary Status Effect Damage.

Grim Reaper
Press and hold ability to spawn a Grim Reader that drains nearby enemies, dealing Status Effect Damage over time, and regenerating Health for each drained enemy.
When an enemy dies while being drained, there is a chance a new Reaper will be spawned.

Pincushion
Haruspex now throws multiple Phase Daggers from both hands in a fan pattern.
Killing an enemy now only refunds a portion of Haruspex's Cooldown.

Prismatic Weaponry
5 points
Vex and her Specters deal Bonus Damage with Gun Critical Hits.
The Bonus Damage will be a random Elemental Type that changes on Reload, and that is increased for each active Attunement.

Banshee's Wail
Minion Skill. Reapers can now use Banshee's Wail periodically, dealing Damage to nearby enemies and granting Overshield to nearby Allies. Damage increases apply to Overshield granted to Allies.
Damaged enemies deal reduced Damage for a Duration

Obedient Fiends
5 points
Vex gains increased Minion Damage.
Minion Skills and Command Skills gain further increased Damage.

Spirit Bomb
3 points
Reapers gain Maximum Health Capacity and will release a Spirit Bomb Remnant when they die, dealing Damage of their Elemental Type to nearby enemies.

Ancient Rites
5 points
Vex gains a stack of Ancient Rites for each of her active Minion(s) every second, increasing Minion Damage.
Stacks are lost after a Duration with no active Minion.

Death Follows Closer
3 points
Whenever Vex takes Damage while at Low Health, Spawn a Reaper nearby.

Diener
1 point
Dead Ringer gains an additional Charge.

Dark Pact
Vex can now equip two Augments, and gains the ability to use Dark Pact.
Dark Pact: Press and hold ability while a Minion is active to fully restore Health of all Phase Clones, as well as granting increased Movement Speed and Minion Attack Speed for a Duration.
Phase Clones do not lose Health over time while Dark Pact is active, and Health loss is reset when Dark Pack ends.