You hold up mana and represent a counterspell or removal spell
Stock Up Okay, hear me out
Gisela, the Broken Blade: Take out the Meld clause, and you have a so-so Mythic
Marvel, Kamala Khan Nerd Rage Nezahal, Primal Tide Niv-Mizzet, Visionary Nyssa of Traken Power Without Equal Praetor's Counsel Proft's Eidetic Memory Reed Richards, Smartest Man Reliquary Tower Roaring Furnace // Steaming Sauna Sea Gate Restoration Spellbook Spirit Water Revival Stairs to Infinity Tamiyo, Seasoned Scholar Tamiyo, the Moon Sage The Great Synthesis The Lux Foundation Library The Magic Mirror The Second Doctor Thought Vessel Tishana, Voice of Thunder Triskaidekaphile Undercity Reaches Venser's Journal Vnwxt, Verbose Host Wisdom of Ages Wizard Class Wrenn and Seven Your Puny Minds Cannot Fathom
Realistically, these lands will make more Cubes than many of the cards in my Top 10 list