Aether Barrier
{2}{U}
Enchantment
Oracle Text
Whenever a player casts a creature spell, that player sacrifices a permanent of their choice unless they pay {1}.
Watch Out
Cast trigger fires even if counteredWatch Out
This triggers when the spell is cast, before it resolves. Even if the spell is countered, the cast trigger still resolves. Copies of spells are not cast, so they won't trigger this.