Jace is the clear best but much of this is down to the great versatility of the card beyond the mere capacity to bounce
While we correctly predicted that Quintorus, Field Historian, would be reprinted, we still have three other upgrades worth considering
This makes it less of a feels-bad than most land destruction, and therefore more acceptable in most pods
That being said, drawing and discarding is still a useful effect, as you can continually search for the cards you need while discarding the ones you dont
There are just three dungeons (right now) but with forking paths that leaves a lot of options in them at various times of the game
Anim Pakal, Thousandth Moon, and Voja, Jaws of the Conclave together since they are incredibly explosive in nature and can quickly shift the game in your favor in a turn or two