The ability to sacrifice it to tutor any other land in a player's deck is certainly powerful, though an effective 4 mana (3 + tapping Urza's Cave) to activate is a steep cost in a format as potentially fast as Modern
(2021-07-23) You can only move forward (well, downward) in a dungeon, never backwards or sideways
Table of contents About Double-Faced Substitute Card Double-Faced Substitute Card, Card, designed by Piotr Dura first released in Sep, 2020 in the set Zendikar Rising Substitute Cards and was printed exactly in 57 different ways
This card is now a part of a Human deck in Standard, which will make some noise this season
Learn was showcased on the Pop Quiz card, which lets players draw a card before also Learning - which is either discarding a card to draw a card, or fetching a Lesson from "outside the game" (in play, this means the player's sideboard)
Then when it ETBs, you can put any number of creatures from your hand to the battlefield