Kirk Cousins, Endless One

When Kirk Cousins enter the battlefield, its power/toughness are equal to the difference
between your health and the opponent with the highest health.
{1}{r}{g}{g}, sacrifice: On the upkeep of your next
turn, return Kirk Cousins to your battlefield.
May only be activated during your turn phases.
When Kirk Cousins is destroyed, exile.
This Creature cannot be enchanted by its owner.