Bug Reports - Helmet Corruption: 90% Mana Multiplier Not Working Correctly - Forum - Path of Exile
Reduced Mana Reserved - The Problem with Stacking and How to Fix It : r/pathofexile
Reservation - Path of Exile Wiki
Best way to lower mana reserved? : r/pathofexile
The Mana Reservation Efficiency mastery has been replaced as there is now a much larger amount of Mana Reservation Efficiency for Curse Auras on the passive tree." (The mastery was 30%) :
Gameplay Help and Discussion - Reduced Mana Reserved Jewel not working - Forum - Path of Exile