Raven, Desert Wanderer

+3: Deal 3 damage to all opponents, and create two 3/2 Sand Elementals with Flying, and Vigilance.
0: Sacrifice any amount of Sand Elementals, you gain Sand Storm counters equal to the total amount of power of all the sacrificed creatures.
-8: You get an Emblem with "At your upkeep, deal damage to all opponents equal to the amount of Sand Storm counters you have."