Let the fans get creative!
Name: (none yet, it's influenced by living a certain way though)
Basically the ability has three parts:
when meat is consumed the strength of nen increases. the longer the user stays without meat, the stronger the nen becomes. The duration of increased nen is dependent on the amount of meat consumed and the duration that meat hasn't been eaten.
after a period of 30 days without consuming meat, the user will forcefully enter zetsu for 24 hours. During this period the user may experience symptoms of withdrawal from the enhanced nen. Symptoms include nausea, vomiting, chills. The stronger the nen has been enhanced, the the stronger the withdrawals become (may include extremely vivid dreams, hallucinations and temporary break down of ordinary reality). Once the user has entered meditative phase, it cannot be cancelled (note: this is different from regular zetsu).
After 24 hours of zetsu, the user's nen becomes more calm and stable. regenerative/recuperative/healing abilities are enhanced during this phase. Staying in zetsu during bliss phase will increase the amount of enhancement the nen will receive on aggression phase.
*The user can enter bliss phase (from aggression phase) without having to wait for 30 days simply by entering meditative phase (24 hours of enforced zetsu, cannot be cancelled)
*The user experiences withdrawals every time he/she transitions from aggression phase to meditative phase
*Meat can be consumed continuously the whole day to slightly strengthen the nen (though the enhancement will be minimal since the strength of the nen is dependent on the time spent without meat and amount consumed) maximum amount that can be consumed is until one get's a full stomach (beyond that makes little difference, just a bad tummy)
*The quality of meat consumed also contributes to the strength of enhancement. (e.g. consuming a nen user's flesh will give a tremendously greater boost)
*The only way to enter aggression phase is through consuming meat, The only way to enter bliss phase is by entering meditative phase.
*Accidentally consuming meat still counts as consuming meat, there's no excuse. (can potentially ruin years worth of charge time)
*An amazingly strong nen can be accessed by spending zetsu on Bliss phase for a VERY LONG AMOUNT OF TIME (decades) and consuming high quality meat (like Meruem's)