Matchprint Color Proofs typically have a white back, because theyre printed on a special Imation Commercial Base paper instead of regular Pokemon cardstock
If they are holding removal or countermagic you can take that away, see what other options they have and then do your own thing with perfect information and safety
While not rare, their simplicity makes them nostalgicthink Base Set Charmander
His 4 Strength, 5 Willpower stats are decent for Challenging (or being Challenged!), and he also has 1 point of Lore for Questing
As the name implies, it's great for control decks, as all artifacts, instants, and sorceries are taxed for one extra mana
While "The Sanctuary in the Sky" is face-up on the field, once per turn, you can discard 1 Fairy-Type monster to select 1 of your removed from play LIGHT Fairy-Type monsters, and Special Summon it