Guide
How the kit works
Cissia enters the battlefield with 3 Venom and one stack of Serpentine Shadow. Use EX Special Attack: Venomous Bite (Special) when you have enough Energy: it grants 3 Venom and can lead straight into the fourth hit of Basic Attack: Tongue Flick. That hit gives 2 Venom, plus one more against a Stunned enemy. Holding the EX spends extra Energy for more strikes and Venom.
Every 6 Venom gained gives one Serpentine Shadow stack, up to three. Hold Basic Attack: Serpent's Kiss to spend a stack and leap at an enemy. You can hold and drag to move the landing point. On a hit, it consumes all Venom and triggers Corrode Bone. Each trigger gives Cissia 6% CRIT Rate for 15 seconds, up to three stacks.
While Cissia has Venom in combat, Core Passive: Fatal Concoction spends one every 5 seconds to trigger Corrode Bone. Each excess point of Venom gained triggers it too. Chain Attack: Gang Operation and Ultimate: Ophidiophobia each grant 3 Venom. The Ultimate also creates Ether Veil: Cold-Blooded for 30 seconds, giving the squad 5% CRIT DMG. Serpent's Kiss triggers a Quick Assist; the EX, Chain Attack and Ultimate trigger one when they hit.
Build and why
Use four pieces of Dawn's Bloom for Basic Attack DMG. Its four-piece effect gives an Attack character another 20% Basic Attack DMG after an EX Special Attack or Ultimate, which fits Cissia's use of Serpent's Kiss (Basic). Add two pieces of Swing Jazz or Moonlight Lullaby for 20% Energy Regen. Four-piece Astral Voice is an alternative: its Quick Assist effect boosts the damage of the character entering through Quick Assist.
For disc 4, choose CRIT Rate. On disc 5, use Electric DMG Bonus or Percent ATK; on disc 6, use Energy Regen. Look for CRIT Rate, CRIT DMG and Percent ATK substats in that order. Energy Regen also matters to Core Passive: Fatal Concoction: initial Energy Regen above 1.4 increases its squad-wide Electric DEF ignore, up to a total of 25%.
Serpentine Seeker is the first weapon choice. It gives CRIT Rate and lets Electric DMG ignore DEF after enough Energy is spent; it also starts combat with that buff. Cordis Germina is next, with CRIT Rate and Electric DMG from stacks built by Basic Attacks or EX Special Attacks. Drill Rig - Red Axis is another option for its Electric Basic Attack DMG boost after an EX Special Attack or Chain Attack.
Leveling priority
Follow the game's order: Core Passive first, then Basic Attack, Special Attack, Chain Attack, Assist and Dodge. Core Passive supports Corrode Bone and the squad's Electric DMG. Basic Attack comes next because Serpent's Kiss (Basic) is a major way to spend Venom, while Special Attack helps generate it.
For maximum ascension, collect 800,000 Denny, 4 Basic Attack Certification Seal, 32 Advanced Attack Certification Seal and 30 Pioneer's Certification Seal. Maxing all skills takes another 2,905,000 Denny, 25 Basic Shock Chip, 75 Advanced Shock Chip, 250 Specialized Shock Chip, 5 Hamster Cage Pass, 9 Exuvia of Refinement and 60 Higher Dimensional Data: Bloodstained Miasma Feather.
Mindscapes worth it
For mindscape targets, I would consider Traveler and Prey first. It raises entry Venom to 6, strengthens the Core Passive's DEF ignore and gives the squad 5% Electric RES ignore. Corrode Bone also ignores 10% Electric RES. Hunger and Hard Truths is useful against Stunned enemies and increases Serpent's Kiss (Basic) DMG by 35%.
A Rogue's Resolve is another target: EX Special Attacks, Chain Attacks and Ultimates build up to three Decidedness stacks. Serpent's Kiss spends them to trigger special Corrode Bone instances without consuming Venom, though those instances do not cause Daze. Home and Sixth Street adds special Corrode Bone triggers when squad attacks hit, with at most one stack consumed every 3 seconds.
Chains and a Warm Nest and False Evidence and Fangs add two levels to the listed skill categories. They are less interesting places to stop if you are looking for a new effect; you can leave them for later rather than target them on their own.
Common mistakes
Do not spend a Serpentine Shadow stack without paying attention to Venom. Basic Attack: Serpent's Kiss consumes all of it on a hit, so plan how you will regain Venom afterward. The squad buffs linger after it runs out, but the timed Corrode Bone triggers need Venom in combat.
Do not forget the fourth Basic Attack after EX Special Attack: Venomous Bite (Special), especially against a Stunned enemy for the extra Venom. When building Cissia, avoid treating Energy Regen as irrelevant: her Core Passive checks its initial value. Also remember that Moonlight Lullaby's four-piece squad effect requires a Support character, so use its two-piece effect on Cissia instead.
