Thoromal, Apex Predator

Apex—Creature spells you cast cost {2} less to
cast as long as you control the creature with the highest power.
As long as an opponent controls the creature with
the highest power, Thoromal, Apex Predator has indestructible.
Whenever Thoromal, Apex Predator attacks, put
a +1/+1 counter on target creature you control.