The card was a prize for CoroCoro readers in Japan, as part of an illustration contest to design their own Pokemon cards
Introduced way back in the 1996 expansion Alliances, before being given the name "Scry" in 2004's Fifth Dawn, scry is a keyword action (instructions to carry out a specific action that doesn't have an inherent trigger, and so can slot into all kinds of cards)
By spreading the mana value of your cards throughout your deck, you'll ensure you have something to cast each turn
These are simple first-purchase options
If you see spots glow on the card, thats a bad sign of possible re-coloring or scratch filler
Ill be largely ignoring that text in this post, since its often too technical to explain succinctly to non-players