Domino Theory

As an additional cost to cast this spell, reveal a
colorless creature card from your hand. Exile target creature if its power is less than or equal to the
revealed card's power.
The domino theory is a geopolitical theory which posits
that changes in the political structure of one country
tend to spread to neighboring countries in a domino effect, suggesting that if one country in a region
came under the influence of communism, then the surrounding countries would follow.