Use Szarekhs recursion ability to pull out your biggest threats
It simply lacked a real solid Mono-White option outside of maybe Abdel Adrian, and now it gets its time to shine here
Advanced Search Sets Random Syntax Ancient Silver Dragon Anvil of Bogardan Body of Knowledge Choice of Fortunes Chronatog Avatar Curiosity Crafter Cursed Rack Day's Undoing Decanter of Endless Water Discontinuity Doctor Octopus, Master Planner Enter the Infinite Finale of Revelation Folio of Fancies Glorious End Gnat Miser Graceful Adept Hurkyl's Final Meditation Inspired Idea Jin-Gitaxias, Core Augur Kruphix, God of Horizons Learned Learner (playtest) Library of Leng Locust Miser Marina Vendrell's Grimoire Midnight Oil Minamo Scrollkeeper Mine, Mine, Mine
TL;DR Direct answer : The best Sapphire cards from Fabled to prioritize are Hades - Infernal Schemer, Aurora - Dreaming Guardian, Dig a Little Deeper, Mulan - Considerate Diplomat, and Cruella De Vil - Style Icon
Or an Infinity Gauntlet card with a specific alternate win condition