The adventure mechanic was a direct response to an issue Set Design came up against: they felt that Vision Designs set was too focused on making big mechanical choices during deck building and not enough during play (Set Design lead Mark Gotlieb has written a full account of how Adventures were designed)
First, they looked back at all the mechanics from the Ixalan block ( Ixalan and Rivals of Ixalan ): Ascend/City's Blessing Explore Enrage Raid Transforming double-faced cards (with lands on the back face) Treasure tokens Typal themes (Dinosaur, Merfolk, Pirate, and Vampire) We wanted to bring back a little bit to make it feel like Ixalan but not too much, as we weren't repeating the mechanical identity
We went back to the drawing board and thought about what else made firebending special
Add in its immediate impact and its upside as a sac outlet and youve got a truly terrifying goblin to deal with
Lorehold, the Historian (Borderless) You already know what to expect here, but Lorehold, the Historians borderless treatment has reached around $24 in value