In short, the flavor text is just a clue to help you figure out the card
You want to be at 0 Life cards and have two Kids in the trash for Gecko Moria to find value
These correspond to a full art Pokemon, a full art Pokemon ex or Supporter card, a full art "immersive" Pokemon ex, and a gold full art card (called a "crown rare")
Lightning Bolt The burn player in me is screaming that not putting Lightning Bolt at #1 is heresy but, well, the times, cards, and formats (and life totals!), they are a-changin'
Treasures are useful because they can accelerate your mana in a pinch, or you can use Magdas payoff effect to find expensive artifacts or Dragons to close the game with, opening up a cool token play pattern that is a breath of fresh air after years of Krenko and Purphoros, God of the Forge combo killing tables by generating a zillion goblins