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%) :
Templar - [3.8] The Everything-ish Aura Guardian - Forum - Path of Exile
New charisma .. : r/pathofexile
For anyone confused about how the numbers work for reservation efficiency I made a little thingamajig to help understand. : r/pathofexile
4 minion 6 link reduced mana reserved helm : r/pathofexile
Gameplay Help and Discussion - Mana Reservation Rounding Question [pics] - Forum - Path of Exile
It Is Now Possible to Achieve 100% Reduced Mana Reserved : r/pathofexile
Path of Exile 3.13] How To Craft My Shield - 15% Reduced Mana Reservation & 10% Aura Effect - 713 - YouTube
Gameplay Help and Discussion - Mana Reservation Rounding Question [pics] - Forum - Path of Exile
Reservation - Path of Exile Wiki
Gameplay Help and Discussion - Amulet with Pride has #% reduced mana reservation - Forum - Path of Exile
Gameplay Help and Discussion - Reduced Mana Reserved Jewel not working - Forum - Path of Exile
POE 3.20: Manabond CwC Hiero Build For Thor
Gameplay Help and Discussion - Impresence Flammability 100% Reduced Mana Reservation is BUGGED. - Forum - Path of Exile
Scion - [3.12] Aura Stacker CI - 50ex Budget Guide | Upgrades to 500ex budget | Immortal - Forum - Path of Exile
Reservation - Path of Exile Wiki
POE 3.19] How to Fit More Auras and Fix Your Mana Cost! Mana Reservation & Cost Guide - YouTube
Beast Charm, a +2% max res, 15% reduced mana reservation life shield for my Blade Blast Chieftain : r/pathofexile