One With Nature is great in green and Enchantress-based builds, and Goldvein Pick can help you stock up mana for later
Power creep on still powerful cards is enough to make Magic players go crazy
With Nadu and Nantuko, every land drop makes more creatures, more creatures means more Nadu triggers, and more Nadu triggers means more land drops
Hateful Eidolon is also nice insurance against opponents killing your own enchanted creatures, of course, but black's ability to proactively draw cards with aura-based creature removal makes this card real good
Plus, if you want to hear about the history of Bloomburrow itself, the Planeswalker's Guide to Bloomburrow (Part 1, Part 2, and Part 3)
It aims to prevent "pub-stomping" (crushing casual players) while avoiding being too weak