Dress Down

Flash
When this enchantment enters, draw a card.
Creatures lose all abilities.
At the beginning of the end step, sacrifice this enchantment.

Doorkeeper Thrull

Flash
Flying
Artifacts and creatures entering don't cause abilities to trigger.

Trample
When this creature enters, sacrifice it unless you sacrifice any number of creatures with total power 12 or greater.

Counter target activated or triggered ability. (Mana abilities can't be targeted.)