Grievous, Droid General

+2: If you don't control an army, create a colorless 1/1 Drone Army creature token named "Battle Droids". Amass 2.
-3: Until end of turn, Grievous, Droid General becomes a 5/5 Drone Warrior creature with Double Strike, Trample and Indestructible.
-10: Amass 5. You get an emblem with "Creatures you control have Double Strike, Trample, and Indestrucible."