As hobbies turn into investments, authentication services in categories of high value have become a priority for collectors
Most of them changed card types, usually changing from Non-Effect Monsters to Effect Monsters or even from Trap Cards to Effect Monsters
Golos, Tireless Pilgrim Percent of Decks Pre-MCV : 21.3% Copies per Deck Pre-MCV: 3.9 Copies in MCV Decks: 114 (6th) Wait, the current bogey man of Standard is only the #7 card in Standard
Secondly, Yu-Gi-Oh
The overarching story easily starred over a hundred characters, not all of which are Planeswalkers, and I'm probably correct in assuming Weisman did not have the time to research all of them before having to write this novel, that's understandable
And if youre after Special Guests cards in foil, these only appear in Collector Boosters and can command a premium depending on the card itself