This should supposedly reduce the win rate of the dominant strategy in the format and create an exciting shake-up and entry point to the format preceding the summer and release of Wilds of Eldraine. Getting into the specifics, Brown highlighted what we all already know, cards like Fable and Bankbuster are unmatched in efficiency and versatility
Hour of Devastation included new creatures with Exert, and while some of them followed the same attack trigger formula, the bonuses they received were smaller, like Khenra Scrapper: +2/+0 until end of turn. Additionally, a small number of creatures could exert as an additional cost of an activated ability, like Hope Tender: Untap two target lands. Hope Tender could provide extra mana, but only every other turn
As a result, he's too powerful
But you can do so much more with it if you add a bit of finesse to how you use it, finding ways to spin its flaws into positives and making the most of how flexible an enchantment it truly is
Unnatural Growth Its a house in Limited, Unnatural Growth looks to be excellent for Green-heavy Commander lists that care about being aggressive
It's also a reference to Unmask, a story-relevant card from the 1999 Magic: The Gathering set Mercadian Masks - Wizards even commissioned the same illustrator