Shut The Front Door

For each Phyrexian Mana spent to cast this spell, discard a card.
For each creature on the battlefield:
• If the creature has toughness 1-4, put 1
door counter on it.
• If the creature has toughness 5-8, put 2 door counters on it.
All creatures gain "If this creature has 0 door
counters on it, exile it at the beginning of
your next end step."