Black Fetin

Black Fetin is one of three special Fetin disorders obtained exclusively through the Volcano event in The Jurassic. When you sacrifice a cat at the volcano and get a rare critical success, the cat survives and receives a random Fetin. Black Fetin's upside fully restores the afflicted cat's mana whenever an ally cat is downed, providing a massive emergency mana injection at the exact moment you need it most. The downside, shared by all Fetins, is a 10% chance each turn for the cat to be AI-controlled instead of player-controlled.

The AI control chance scales heavily with Luck. At the neutral baseline of 5 Luck, the chance is exactly 10%. Stacking Luck to 15 drops it to just 1%, making the downside nearly negligible. At -7 Luck the chance rises to about 20%, and at deeply negative values it can exceed 60%. When the AI takes over, it prioritizes nearby enemies with basic attacks, disregards on-contact effects like Thorns and Poisonous, ignores Counter Attack and Backflip on targets, and may attack downed allies or familiars if they block the path to an enemy. Keeping Luck reasonably high is essential for any Fetin build.

What makes Black Fetin arguably the most powerful of the three is its synergy with abilities that intentionally down allies. Flatline, Play Dead (Collarless), and Seppuku (Necromancer) all allow controlled ally downing, turning Black Fetin's trigger from a situational emergency refill into an on-demand full mana restore you can activate every fight. This enables explosive ability rotations on cats with expensive, high-impact spells. In Necromancer or Collarless team compositions, a Black Fetin cat effectively has unlimited mana as long as allies can cycle through downed states. Even without deliberate downing synergies, the disorder provides a powerful comeback mechanic that can fuel a fight-saving ability rotation right when an ally falls. Fetin disorders are classified as Special Disorders, excluded from all normal disorder pools, so the only way to obtain one is through the Volcano sacrifice.