Dreadful Duo, Android 18

[Critical] (When this card inflicts damage to your opponent's life, they place that many cards in their Drop Area instead of their hand) [Activate: Main] [Once per turn]: During that turn, if an opponent's Battle Card with an energy cost of 4 or more has been placed in the Drop Area from any area by one of your skills, choose up to 1 of your opponent's Battle Cards with an energy cost of 3 or less. KO that card.