Wizards expanded on the mechanic in 2018s Battlebond with the less flexible Partner with on 22 additional cards, which only allowed players to partner specific legends together
Because the typal theme was so strong, it drove the mechanical themes of the draft archetypes
It has 23 printings, including 7 different core sets (counting Alpha through Unlimited as one) and one set (Darksteel)
Leaning in would mean playing some fun cards that have no other home, like Confusion in the Ranks, Forgeborn Oreads, and various other blue enchantments you like
There was nothing intrinsically wrong with putting shocklands in Unfinity to provide a wee bit of value, but doing away with the silver border and making ridiculous fiddly mechanics like stickers playable in eternal formats was a misstep
A 1/2 goblin pirate that creates treasure tokens equal to the number of artifacts and enchantments your opponents control, which could easily provide an advantage for the rest of the game, all for just 2 mana