Its kind of like an investment in your future self in each game
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
That's the mana cost it takes in order to activate this ability

1 Kasla, the Broken Halo 1 Saint Traft and Rem Karolus 1 Wand of the Worldsoul 1 Flockchaser Phantom 1 Wildfire Awakener 1 Ichor Elixir 1 Path of the Ghosthunter 1 Deluxe Dragster 1 Mistmeadow Vanisher 1 Nesting Dovehawk 1 Kykar, Wind's Fury 1 Elspeth, Sun's Champion 1 The Locust God 1 Angel of Finality 1 Angel of Salvation 1 Austere Command 1 Chasm Skulker 1 Cultivator's Caravan 1 Emeria Angel 1 Exotic Orchard 1 Frostboil Snarl 1 Furycalm Snarl 1 Hour of Reckoning 1 Keeper of the Accord 1 Kher Keep 1 Mentor of the Meek 1 Nadir Kraken 1 Port Town 1 Prairie Stream 1 Secure the Wastes 1 Skycloud Expanse 1 Temple of Enlightenment 1 Temple of Epiphany 1 Temple of Triumph 1 Venerated Loxodon 1 Whirlwind of Thought 1 Cloud of Faeries 1 Command Tower 1 Commander's Sphere 1 Ephemeral Shields 1 Evolving Wilds 1 Fractured Powerstone 1 Goblin Instigator 1 Goblin Medics 1 Impact Tremors 1 Spirited Companion 1 Suture Priest 1 Terramorphic Expanse 1 Village Bell-Ringer 1 Banisher Priest 1 Arcane Signet 1 Battle Screech 1 Chant of Vitu-Ghazi 1 Conclave Tribunal 1 Devouring Light 1 Duergar Hedge-Mage 1 Fallowsage 1 Flight of Equenauts 1 Improbable Alliance 1 Migratory Route 1 Mystic Monastery 1 Rogue's Passage 1 Seraph of the Masses 1 Skullclamp 1 Sol Ring 1 Stoke the Flames 1 Swords to Plowshares 1 Tetsuko Umezawa, Fugitive 1 Wear // Tear 1 Temporal Cleansing 1 Meeting of Minds 1 Shatter the Source 1 Wrenn's Resolve 1 Cut Short 1 Joyful Stormsculptor 1 Artistic Refusal 8 Plains 8 Island 8 Mountain Divine Convocation Planechase Cards Divine Convocation Tokens 1 Bird // Kobolds of Kher Keep token 1 Spirit (white) // Spirit (blue) token 1 Warrior // Emblem (Elspeth, Sun's Champion) token 1 Soldier // Insect token 1 Eldrazi // Angel (4/4) token 1 Squid // Human (red) token 1 Tentacle // Human (red) token 1 Goblin // Eldrazi token 1 Elemental // Elemental (blue-red) token 1 Elemental // Faerie token Bird // Kobolds of Kher Keep Spirit (white) // Spirit (blue) Warrior // Emblem (Elspeth, Sun's Champion) Soldier // Insect Eldrazi // Angel (4/4) Squid // Human (red) Tentacle // Human (red) Goblin // Eldrazi Elemental // Elemental (blue-red) Elemental // Faerie CALL FOR BACKUP Bright-Palm, Soul Awakener and Shalai and Hallar are traditional foil cards

While it is true that the effects of the Reserved List are almost all negative for the average Magic player today, if we take a time machine back to 1996 when the list was created, the Magic world looked very different