Mox Diamond [From the Vault: Relics] Tempest Promos when a monster effect is

when a monster effect is activated on your opponent's side of the field: You can detach 1 Xyz Material from this card

If this card is sent to the Graveyard: You can send 1 Fiend-Type monster from your Deck to the Graveyard

or Effect Monster's effect

Set: Dark Revelation Volume 1 Card type: Fusion/Effect Monster Rarity: Rare Attack: 800 Defense: 600 "Spirit Reaper" + "Nightmare Horse" This card is not destroyed as a result of battle

Mox Diamond [From the Vault: Relics] Tempest Promos when a monster effect isSet: From the Vault: Relics Type: Artifact Rarity: Mythic Cost: {0} If Mox Diamond would enter the battlefield, you may discard a land card instead. If you do, put Mox Diamond onto the battlefield. If you don't, put it into its owner's graveyard. {T}: Add one mana of any color.