As an example, in blue control mirror matches, counterspells become much more valuable as they can make or break a game
Pokmon Tournament Rules Handbook states that Cards that have undergone post-production alteration, [including] autographs, artwork, or other such amendments to the surface of the card, not including any official stamps applied by TPCi [are disallowed]. Like altered cards, damaged cards are also not legal for tournament play if their damage is substantial enough to potentially be visible during play
However, in some unusual situations, no cards in your library share a card type with the permanent (perhaps because the permanent was a token or its types were changed)
For the cost of two mana, Jhoira can suspend cards, exiling them for four turns with four time counters on them, removing a counter at the beginning of each of your turns
When you already own four copies of every rare in a set, opening that sets packs converts duplicate rares into 20 gems each