So, I built the deck up
An Izzet deck is spoiled for choices, and these dont make the list, but Nivix Cyclops, Piston-Fist Cyclops, & Prismari Pledgemage will always be on. #21
These cards are some of the first to ever hit the shelves and usually have a limited print run before being replaced by regular versions

The Final Days Gaius van Baelsar Hecteyes Braska's Final Aeon (Jecht, Reluctant Guardian // Braska's Final Aeon) Jecht, Reluctant Guardian (Jecht, Reluctant Guardian // Braska's Final Aeon) Kain, Traitorous Dragoon Malboro Namazu Trader Ninja's Blades Overkill Phantom Train Poison the Waters Qutrub Forayer Reno and Rude Resentful Revelation Sephiroth, One-Winged Angel (Sephiroth, Fabled SOLDIER // Sephiroth, One-Winged Angel) Sephiroth, Fabled SOLDIER (Sephiroth, Fabled SOLDIER // Sephiroth, One-Winged Angel) Sephiroth's Intervention Shambling Cie'th Shinra Reinforcements Yiazmat, Ultimate Mark (Sidequest: Hunt the Mark // Yiazmat, Ultimate Mark) Sidequest: Hunt the Mark (Sidequest: Hunt the Mark // Yiazmat, Ultimate Mark) Summon: Anima Summon: Primal Odin Tonberry Undercity Dire Rat Vayne's Treachery Galian Beast (Vincent Valentine // Galian Beast) Vincent Valentine (Vincent Valentine // Galian Beast) Vincent's Limit Break Shinryu, Transcendent Rival (Zenos yae Galvus // Shinryu, Transcendent Rival) Zenos yae Galvus (Zenos yae Galvus // Shinryu, Transcendent Rival) Zodiark, Umbral God Barret Wallace Blazing Bomb Call the Mountain Chocobo Choco-Comet Ifrit, Warden of Inferno (Clive, Ifrit's Dominant // Ifrit, Warden of Inferno) Clive, Ifrit's Dominant (Clive, Ifrit's Dominant // Ifrit, Warden of Inferno) Coral Sword The Fire Crystal Fire Magic Firion, Wild Rose Warrior Freya Crescent Gilgamesh, Master-at-Arms Haste Magic Hill Gigas Item Shopkeep Laughing Mad Light of Judgment Mysidian Elder Nibelheim Aflame Opera Love Song Prompto Argentum Queen Brahne Random Encounter Raubahn, Bull of Ala Mhigo Red Mage's Rapier Sabotender Samurai's Katana Sandworm Seifer Almasy Self-Destruct World Champion, Celestial Weapon (Sidequest: Play Blitzball // World Champion, Celestial Weapon) Sidequest: Play Blitzball (Sidequest: Play Blitzball // World Champion, Celestial Weapon) Sorceress's Schemes Summon: Brynhildr Summon: Esper Ramuh Summon: G.F

Clamp is not always suitable to play as you not only need the creature count but specifically the disposable creature count
Mind you, Im not a hardcore CCG player, and I dont usually seek these experiences out, but Ive got a few friends who play these games competitively or judge competitions, and I trust their assessment based on the Lorcana starter sets