Vaal skill

Vaal skills are granted by Vaal skill gems, a special type of corrupt skill gem that grants an alternative version of the skill with powerful added effects fueled by the souls of slain enemies, as well as the regular version of the skill.

Vaal skill gems can be looted from vaal side areas, certain strongboxes, certain divination card, and bosses of corrupted maps. It is also possible to create a Vaal skill gem by using a Vaal Orb (or Lapidary Lens) on a corresponding normal skill gem (e.g. using a Vaal Orb on Spectral Throw has a chance of turning it into Vaal Spectral Throw).

Mechanics

Vaal skill gems grant both the base version of the skill and the Vaal version of the skill. Anything supported to the Vaal skill gem will apply to both skills, as long as they're applicable.

Souls

To use a Vaal skill, its gem must first be charged by collecting souls. Souls can be obtained by killing enemies, granting 1 souls per kill. Souls can also be obtained when damaging Rare or Unique enemies (1 or 6 souls, respectively, per 2% life lost with a 1 second cooldown). Each soul gained will charge a random Vaal skill equipped on the character. Souls will never charge a Vaal skill in the character's secondary weapon set. Souls are also tracked per skill, not per gem. In other words, you cannot store multiple charges of the same skill by equipping multiple copies of the Vaal skill gem.

Collected souls cannot be transferred between zone instances; instead, each instance maintains its own soul counter for each gem. Therefore, entering a new instance will start a new counter for each gem but returning to a previously visited instance will restore each counter to its previous value.

Once a Vaal skill collects a sufficient number of souls, it is charged with one use. The number of souls per use depends on the skill. Some Vaal skill gems can store enough souls for more than one use. Once a gem's maximum soul capacity is reached, it can collect no additional souls until they are spent by using the skill. Once used, the Vaal skill will be unable to gain souls for a few seconds. The length of soul gain prevention time varies between skills, and effects that modify the duration of the skill will also modify the duration of the soul gain prevention time. The soul gain prevention is global, which means you will not be able to gain any souls for any vaal skill at all.

A vaal gem that collected souls in an instance will keep these souls during a gem swap, a drop on the ground or putting it in the inventory afterwards.

Party - All players near monsters killed gain the same number of vaal souls as if they had killed it alone. Therefore characters who do not kill can still gain vaal souls in a party. In a party all kills by a player with Soul Eater will not give vaal souls to the party.

Soul Eater will prevent solo characters from gaining any vaal souls during the buff effect.

Sextants can apply the following modifiers to maps:

• Players' Vaal Skills do not apply Soul Gain Prevention.
• Players gain an additional vaal soul on kill.

Other mechanics

Vaal skills cannot be supported with Multistrike Support, Ancestral Call Support, and Spell Echo Support.

Vaal skills themselves can not be activated by trigger effects, but they can be used as a trigger.

Any effects that modify the original skill, such as Helmet Enchantments and Threshold jewels, will also affect the Vaal version of the skill as well.

Even if a Vaal skill has a gem tag that doesn't apply it to the base version, both versions will have that gem tag. For example, a Vaal Impurity of Fire skill gem will have the Duration tag on both Purity of Fire and Vaal Impurity of Fire and are affected by modifiers such as +X to Level of Socketed Duration Gems, while a normal Purity of Fire skill gem won't be.

Because a Gemcutter's Prism can't be used on corrupted gems, getting quality on vaal gems is substantially harder than it is on a regular gem. Vaal gems must either drop with quality or a normal gem already with quality must have a Vaal Orb used on it and be turned into a corrupted Vaal gem.