The Zol'bah, Masked Merchant

As an additional cost to cast this spell, you may exile any number of non-token permanents, or cards from your hand. This spell costs {1} less to cast for each card exiled this way.

When this creature enters the battlefield, exile the
top X cards of your library. Until the end of your next turn, you may play those spells, spend any color of mana to cast those spells, and their cost is reduced by X