While he was always a cool character, it wasnt really until Dominaria came out in 2018 that he cemented himself as a worthwhile card, at least outside of Commander
Creatures they begin to control later in the turn won't change power and toughness
In fact, many of the best stuff running around is oriented toward the big side (Stoneforge Mystic, Restoration Angel, Teferi, Mage of Zhalfir, Consecrated Sphinx, Vampire Nighthawk, Gray Merchant of Asphodel, Feldon of the Third Path, Azusa, Lost of Seeking, Silklash Spider, Courser of Kruphix, Prophet of Kruphix, Brago, King Eternal, Kuldotha Forgemaster), and thats in addition to creatures specifically designed and included for defense like Walls and other cards with defender
Make your biggest creature even bigger
Chaos: Whenever you roll Chaos, put target permanent on top of its owner's library
You're likely to run into an issue where you make a huge mass of Oozes, only to realize that you need to wait until the next turn to attack
