Rilzranth, Breaker of Worlds

Flying, Double Strike, Indestructible
As long as your devotion to red and black is less
than 7, Rilzranth isn't a creature.
At the beginning of combat on your turn,
destroy up to 3 permanents target player controls
Whenever a Dragon you control attacks, it gets
+0/+1 and gains Hexproof and Indestructible
until your next turn