Greyoll's Roar

Dragon Communion (This card counts as a Dragon
spell as you cast it.)
Each creature your opponents control gets two -1/-1 counters.
Each planeswalker your opponents control loses 2
loyalty counters.
Greyoll's War deals 4 damage to each planeswalker
and creature your opponents control, and 4 damage
to each opponent. Damage dealt this way cannot be prevented and each permanent destroyed this way is exiled instead of going to the graveyard.