Reference to a set of powerful cards in Magic the Gathering.
The Moxen or Moxes are a collection of powerful gems infused with one of the colors of mana — Mox Pearl for white, Mox Sapphire for blue, Mox Jet for black, Mox Ruby for red, and Mox Emerald for green.
A set was owned by Liana of Minorad. Liana gave them to Kristina of the Woods and Jared Carthalion during her duel with Ravidel at Minorad so that he would not take them. Ravidel claimed various times that the Moxen had once belonged to him; at the battle with Jared, Kristina, Altair of Coloni and Caliphear the Nightmare against Ravidel at the Dueling Chasm of Golthonor, Ravidel used the Mox Jet, Ruby, and Sapphire to activate the Mox Beacon.
Apart from those five original Moxen, two others are known to exist: Mox Diamond and Chrome Mox on Mirrodin.
A set of Moxen costs a bomb.