Cadaverous Tilling (Blue)

Decompose is a label keyword.

Decompose is an optional effect and the effect itself does not target. When the effect resolves, you may choose the cards in your graveyard to banish. If you choose to resolve the decompose effect, you must be able to banish 2 Earth cards and an action card from your graveyard.

To decompose, you need to banish 3 cards in total: two Earth cards, and one action card. The Earth cards may be action cards, and the action card may be an Earth card. Banishing an Earth action card will count towards either one of the two Earth cards being banished or the action card being banished, not both at the same time.