Shateiel, One of Silence

+1: Until your next upkeep, you may choose to remain silent and cast no spells. If you do, place a silence counter on Shateiel, One of Silence.
-1: Tap any amount of mana. This group of mana is a counter for sorceries, instants, or abilities. Others may pay the same mana to counter this.
-7: Place Shateiel, One of Silence into your library and shuffle it. Turn X silence counters into an X/X token creature that can tap for X mana.