As always, it's difficult to predict which cards in Shimmering Skies will prove the most competitive in the long run, but some are clearly impressive options from the start
I normally dont care much for generic good-stuff commanders in three or more colors, but this one feels great

Ifrit Suplex Thunder Magic Triple Triad Unexpected Request Vaan, Street Thief Warrior's Sword Zell Dincht Airship Crash Ancient Adamantoise Balamb T-Rexaur Bard's Bow Bartz and Boko Blitzball Shot Cactuar Chocobo Kick Chocobo Racetrack Clash of the Eikons Coliseum Behemoth Commune with Beavers Diamond Weapon The Earth Crystal Summon: Esper Maduin (Esper Origins // Summon: Esper Maduin) Esper Origins (Esper Origins // Summon: Esper Maduin) Galuf's Final Act Gigantoad Goobbue Gardener Gran Pulse Ochu Gysahl Greens Jumbo Cactuar Loporrit Scout Prishe's Wanderings Quina, Qu Gourmet Reach the Horizon A Realm Reborn Ride the Shoopuf Rydia's Return Sazh Katzroy Sazh's Chocobo Black Chocobo (Sidequest: Raise a Chocobo // Black Chocobo) Sidequest: Raise a Chocobo (Sidequest: Raise a Chocobo // Black Chocobo) Summon: Fat Chocobo Summon: Fenrir Summon: Titan Summoner's Grimoire Tifa Lockhart Tifa's Limit Break Torgal, A Fine Hound Town Greeter Traveling Chocobo Vanille, Cheerful l'Cie Absolute Virtue Balthier and Fran Black Waltz No

Other than building a deck around a specific card and being best played with groups of four, the two have very little in common
If you're curious which cards are in highest demand right now, either to cash in or just to see what the hype is all about, here's a few handy pointers on what to look out for