Whenever you cast a spell from anywhere other than your hand, you may copy it
Competitive cards tend to fall into one of a few categories: they offer game-changing effects, enable consistent draw/search power, provide strong single-prize or multi-prize value, or have synergy with existing top-tier decks
So overall, if you look at Krokorok and Sandile combined, I would probably give these two cards a 1 out of 5 rating, they are both below average individually and terrible together, I would look elsewhere for darkness type Pokemon for your deck
I've heard similar stories from other players
Hisuian Zoroark VSTAR #147 Pokemon Lost Origin Keep track of your collection value over time
With 34 cards over $10, the set has strong chase card appeal