Verified for patch 16.8.1

Void Coefficient

Each cast reduces Mana Cost by 15% (to a minimum of 10)

Source

Effects

PercentManaReductionPerCast
0.15

Void Coefficient enables

  • Mana On the Menu

    The unit-level resource that gates ability casts. Mana-gen items, on-cast refunds, and starting-mana augments all key off this mechanic.