Its maybe the worlds most complex game ever made (with almost 20.000 unique cards printed), but they managed to split their development and design to both very enfranchised players and new ones, making the game still interesting for long time fans and accessible to anyone who is trying to become a player
Springans Kitt is a good option, although it's not ideal for card advantage since it requires you to return a card from your hand to the deck to resolve its search effect
Holo Gold Star Torchic Printed gold star cards are hard to come by, and well-preserved copies are even rarer
Plaxcaster Frogling Shroud is a strong ability to have on tap, and Plaxcaster Froglings graft ability can set up a key creature with some much needed on-demand protection
Any Common, Uncommon, or Rare card can also come in a reverse holo version
The 1999 Pokmon Fossil 1st Edition series was WOTC's third Pokmon release