Mono-Green Landfall relies heavily on Earthbender Ascension and the land Ba Sing Se to power up its board, so Origin of Metalbending gives us a clean way to blow up Earthbender Ascension, denying their scaling plan. Voice of Victory prevents their few instants like Royal Treatment from saving creatures against our removal on our turn. Lost in the Maze and Prismari Charm's small damage mode are weak against a deck built around big, hard-to-kill creatures like Mightform Harmonizer and Icetill Explorer, so they come out for more targeted answers. Since this is a straightforward green ramp-and-go-wide deck without much interaction, focus on stabilizing the board and resolving our own late-game threats.