Emerald Medallion

(28/07/2023)
If a spell you cast has in its mana cost, you choose the value of X before calculating the spell's total cost.

(28/07/2023)
If there are additional costs to cast a spell, or if the cost to cast a spell is increased by an effect (such as the one created by Thalia, Guardian of Thraben's ability), apply those increases before applying cost reductions.

(28/07/2023)
The cost reduction can apply to alternative costs such as flashback costs.

(28/07/2023)
The ability can't reduce the amount of colored mana you pay for a spell. It reduces only the generic mana component of that cost.

(28/07/2023)
The ability doesn't change the mana cost or mana value of any spell. It changes only the total cost you pay.