Each opponent sacrifices an artifact. For each artifact sacrificed this way, you create a Treasure token (A Treasure is an artifact with ", Sacrifice this artifact: Add one mana of any color."). Flashback (You may cast this card from your graveyard for its flashback cost. Then exile it.). This spell costs less to cast this way, where X is the greatest mana value of a commander you own on the battlefield or in the command zone.