We thought Commander was the right goal for a character this popular, so we gave him a three-color color identity and an ability that helped an opponent, which plays better in multiplayer than in two-player games
Ultimately, priority is much more about keeping the game flowing and easy to understand than a mechanic you can use to trick or outplay opponents
Phyrexian Metamorph for the #2 spot

Abbot of Keral Keep Agent of Atlas Aligned Heart Bearer of Overwhelming Truths Bedlam Reveler Bloodfire Expert Bloodwater Entity Bria, Riptide Rogue Cori-Steel Cutter Crescent Island Temple Crimson Operative Cursed Firebreathing Yogurt Cyclops Superconductor Disciples of the Inferno Dragon Bell Monk Dragon-Style Twins Drake Hatcher Dwarven Forge-Chanter Ecstatic Electromancer Elemental Eruption Elementalist Adept Elsha of the Infinite Elsha, Threefold Master Elusive Otter Elusive Otter Emberheart Challenger Eris, Roar of the Storm Firebending Student Frenzied Geistblaster Fugitive Codebreaker Gitaxian Spellstalker Goblin Wizardry Harmonic Prodigy Heartfire Immolator Iguana Parrot Ingenious Skaab Iron Fist, Hero for Hire Jaya, Fiery Negotiator Jeskai Brushmaster Jeskai Elder Jeskai Revelation Jeskai Sage Jeskai Student Jeskai Windscout Jhessian Thief Khenra Spellspear Kitsa, Otterball Elite Kree Commandos Lightning Visionary Lightshell Duo Lilah, Undefeated Slickshot Lotus Path Djinn Lotus-Eye Mystics Lyse Hext Mage-Ring Bully Mai, Jaded Edge Master Pakku Meticulous Artisan Mistfire Adept Mistral Singer Molten Lavamancer Monastery Mentor Monastery Swiftspear Monica Rambeau Narset, Enlightened Exile Niblis of Dusk Niblis of Frost Nimble-Blade Khenra Otterball Antics Patriot, Young Avenger Pearl Lake Ancient Photon, Living Light

Basically, cards which go above the standard numbering are Secret Rare cards
Then you can replay lands from your graveyard that you have milled with the classic artifact Crucible of Worlds