Kamigawa block (2004) Besides the first appearance of a gold card in the updated frame, Kamigawa block also created the flip cards, that would have different rules for each side
This keeps them from being too powerful in Modern
Cards in the Wilds of Eldraine main set create six different Role tokens: Cursed, Monster, Royal, Sorcerer, Wicked, and Young Hero
Jubilant Skybonder - a 2/2 flying Human Wizard, Jubilant Skybonder nevertheless offers incredible synergy for Birds, with an ability that essentially gives them Ward 2 Soulcatcher Aerie - this obscure two-mana enchantment makes it so that each bird that dies adds a counter to the Aerie, which has a static ability that gives each bird in play +1/+1 for each counter on it
Its just hard to both activate and maintain especially with so many cards in multiplayer that nuke entire graveyards at once