Overview & Serpent's Subtlety
Skirk has two main ways of dealing damage, which she can use to be a dedicated on-field DPS with long field-time, a Burst DPS that can use her Burst and swap out, or mix and match depending on the situation. These are accessed through the different versions of her Elemental Skill and Elemental Burst.
Skirk does not interact with traditional Energy. Instead, she has a unique resource called ‘Serpent’s Subtlety’. She is able to gain Serpent’s Subtlety through her Elemental Skill as well as absorbing ‘Void Rifts’. Void Rifts are generated passively whenever any team member triggers a Cryo-related Elemental Reaction except for Melt. Skirk will almost always be played in Freeze teams, so the Reaction that will provide these to her will most often be Freeze.
Void Rifts
Void Rifts are generated when Freeze, Superconduct (and Stellar-Conduct), Cryo Swirl or Cryo Crystallize are triggered. Void Rift generation has a cooldown of 7.5 seconds, and up to 3 can be on the field at once. Skirk is able to absorb a Void Rift through 3 different methods: using the Hold version of her Skill, the non-damaging version of her Elemental Burst, or using a Charged Attack during her Normal Attack mode. The latter two are only accessible through the Tap version of her Skill. Each Void Rift absorbed through any of these methods will grant Skirk 8 Serpent’s Subtlety. Skirk teams tend to run 20+ second rotations, so there will usually be 3 Void Rifts on the field by the time Skirk enters.
Elemental Skill
Skirk’s Elemental Skill can be either Tapped or Held. When Skirk holds her Skill, she will grant herself 45 Serpent’s Subtlety and immediately absorb all nearby Void Rifts.
If she Taps her Skill instead, she will gain 45 Serpent’s Subtlety and enter a special stance called ‘Seven-Phase Flash’. During Seven-Phase Flash, she gains a non-overrideable Cryo Infusion and significantly powers up her Normal and Charged Attacks, including changing the animations for some of them. She will also modify her Elemental Burst to a non-damaging version that can absorb Void Rifts and further buff her Normal Attacks.
While in this mode, Skirk will consume roughly 6.66 Serpent’s Subtlety per second, and if she runs out of it she will exit Seven-Phase Flash. The maximum duration of this mode is 12.5 seconds, which requires about 84 Serpent’s Subtlety. This is fairly easy to achieve, as it only requires 5 total Void Rifts to be absorbed through either her Charged Attack or Burst. Since Skirk can only absorb 3 Void Rifts at a time, she’ll want to take an absorption action twice – either using her non-damaging Elemental Burst and a Charged Attack or two Charged Attack. When hitting an enemy with any attack in this mode, Skirk will generate 4 Cryo Particles. This has a cooldown of 15 seconds, so Skirk will only generate 4 Cryo Particles per rotation. Both versions of her Elemental Skill have a cooldown of 8 seconds.
Elemental Burst
Skirk’s Elemental Burst also has two different modes, called Havoc: Ruin and Havoc: Extinction. Havoc: Ruin is what Skirk has access to at a baseline. It can only be cast when Skirk has 50 or more Serpent’s Subtlety and will consume all Serpent’s Subtlety, dealing increased damage with each additional point over 50 she consumes. Up to 12 Serpent’s Subtlety points will count for this, meaning she gains maximum value at 62 points. Havoc: Ruin will always unleash 5 Cryo strikes with a large AoE regardless of the amount of Serpent’s Subtlety absorbed, and the extra amount of damage will apply to all 5 of these hits. A fully stacked Burst will deal just shy of 4000% talent value at talent level 10, which corresponds to roughly one third of the talent value Skirk is able to do over the entirety of her Tap Skill field time. When this Burst hits an enemy it will also generate 4 Cryo Particles, though this shares the 15 second cooldown with her Seven-Phase Flash particle generation. Using Havoc: Ruin does NOT lock Skirk out of Tap Skill. It is entirely possible for Skirk to use Havoc: Ruin and go into Seven-Phase Flash back to back. Skirk will usually to use her Hold Skill to access Havoc: Ruin, so this is only applicable when that isn’t the case.
Havoc: Extinction is only accessible while Skirk is in Seven-Phase Flash. On cast, it will absorb all nearby Void Rifts and grant Skirk’s next 10 Normal Attacks additional talent value depending on the number of Rifts absorbed, maxing out at 20% with 3 absorbed Rifts. While not a massive DPS increase, it tends to be a little better than absorbing Rifts with a Charged Attack. Havoc: Ruin and Havoc: Extension have a shared cooldown of 15 seconds.
Passives & Teambuilding Restrictions
Skirk gains a direct multiplier to her damage depending on the amount of Hydro and Cryo teammates. When a Cryo teammate deals Cryo damage or a Hydro teammate deals Hydro damage, Skirk will get a stack of ‘Death’s Crossing’. At 1/2/3 of these stacks, Skirk will deal 110% / 120% / 170% of her Seven-Phase Flash Normal Attack damage and 105% / 115% / 160% of her Havoc: Ruin damage. A Skirk with 3 other Cryo or Hydro teammates is about 40% stronger than a Skirk with 2 such teammates, making it essentially always worth it to use 3 outside of certain niche endgame scenarios.
To further reinforce this, Skirk will give all team members +1 to their Elemental Skill talent level if all teammates are Cryo or Hydro. In a team of Skirk / Escoffier / Furina / Cryo or Hydro Flex, this is going to be a 5-6% team DPS increase.