This card features the logo of the 20th Anniversary Festa
Alone, Celestine can bring back creatures three mana value or less, which is very on-theme for white reanimation
Harmonious Archon can often be enough to close the game, too, turning all of your 1/1 creatures into more formidable combatants
You can still transition into a more controlling deck with Cataclysmic Gearhulk and Planar Outburst as sweepers and Tireless Tracker drawing cards, but I expect Kaladesh Standard to be quite fast, so that plan is likely reserved for aggressive Humans decks and things like red aggro
A flash-speed Vedalken Orrery on legs for your legendary and artifact spells is enough to love him, but to add that Panharmonicon-meets-Drivnod, Carnage Dominus-esque ability to artifact and legendary permanents is wild
6 Marath, Will Of The Wild A flexible Naya (green, red, and white) commander introduced in Commander 2013, Marath, Will Of The Wild is a three-mana Elemental Beast that enters the battlefield with a number of +1/+1 counters on it equal to the amount of mana spent to cast it