Spells you cast cost {3} less to cast if they were originally printed in the following expansions or associated commander decks, depending on who won the Unknown event on February 18th, 2023:
Mirran Victory — Mirrodin, Darksteel, Fifth Dawn, and Scars of Mirrodin.
Phyrexian Victory — Mirrodin Besieged, New Phyrexia, All Will be One, and March of the Machine.