Theres a great deal of cards and choices to be made here, but one crucial thing to think about is your win condition
Among the most popular are Pauper, which only uses common and uncommon-rarity cards, formats that limit cards to only specific generations (Unova, Kalos and Alola being the big three), and Theme Pool that uses any card printed in a preconstructed theme deck
Alolan Exeggutor Morelull Alolan Marowak Turtonator Alolan Vulpix Pyukumuku Tapu Fini Tapu Lele Cosmog Minior Pikipek Bewear Celestial Guardians Museum 3 Even harder to come by, these five ex cards are all two Gold Star rainbow rare cards
I am bullish on this going without reprint for quite a while and if it does, its going to continue going up a few bucks a year, possibly at an accelerating rate
It can be mass artifact animation, turning a bunch of Treasure and Clue tokens into creatures, though its an all-or-nothing ability that affects all your tokens