Each spell you cast with a name printed in a Kamigawa expansion costs less to cast.
[+2]: Open up to one sealed Kamigawa booster pack and shuffle those cards into your booster pile. Look at the top four cards of your booster pile. Put two of those cards into your hand and the rest into your graveyard.
[−3]: Return a creature card with a name printed in a Kamigawa expansion from your graveyard to the battlefield.
Heroes of Kamigawa can be your commander.