Sphere of Annihilation AFR/121

Set: Adventures in the Forgotten Realms
Collector Code: AFR/121
Name: Sphere of Annihilation
Type: Artifact
Oracle text: This artifact enters with X void counters on it. At the beginning of your upkeep, exile this artifact, all creatures and planeswalkers with mana value less than or equal to the number of void counters on it, and all creature and planeswalker cards in graveyards with mana value less than or equal to the number of void counters on it.
Rarity: Rare