Archmage Support is a Support gem that changes the linked spell's base mana cost to be equal to a proportion of your unreserved mana. It gives the skill added Lightning damage based on how much mana was spent to cast that skill.
Armageddon Brand
Armageddon Brand of Recall
Armageddon Brand of Volatility
Automation
Awakened Added Chaos Damage Support
Awakened Added Lightning Damage Support
Awakened Blasphemy Support
Awakened Cast While Channelling Support
Awakened Controlled Destruction Support
Awakened Elemental Focus Support
Awakened Enlighten Support
Awakened Hextouch Support