Mox Opal [Modern Masters 2015] Goblin Artificer A grave is the safest

A grave is the safest place to store ill-gotten treasures

that many plus one of each of those kinds of counters are put on that permanent instead

Then that player loses all unspent mana and you add the mana lost this way

Repeat this process until no one puts a card onto the battlefield

Set: From the Vault: Relics Type: Artifact Rarity: Mythic Cost: {1} {T}: Add {C}{C}

Mox Opal [Modern Masters 2015] Goblin Artificer A grave is the safestSet: Modern Masters 2015 Type: Legendary Artifact Rarity: Mythic Cost: {0} Metalcraft {T}: Add one mana of any color. Activate only if you control three or more artifacts. The suns of Mirrodin have shone upon perfection only once.