Dreadnaught Leviathan

Dreadnaught Leviathan can't be countered.
Islandwalk, trample, protection from blue
Whenever you draw a card, you may sacrifice
two Islands. If you do, Dreadnaught Leviathan
deals 7 damage to each other nonblue creature
and each planeswalker. For each planeswalker
that would die this way, draw a card.