Rites of Flourishing is a group hug card that helps all players equally, but it creates a problem in other strategies because you spend your mana on a card that helps everybody
Derevi loves to fill up with cheap utility creatures, including all the mana dorks like Llanowar Elves
Destroying all creatures you dont control is a brilliant effect, and one that is actually quite rare across Magics history, with only one other card being printed with that text: the strictly better In Garruks Wake from Magic 2015
Confidant, Xathrid and Blasting Station really make me smile
It gets you started early by virtue of being a 0-power creature, and itll put a +1/+1 counter on a creature you control regardless of if you have three differently-powered creatures
As with Soul Foundry, the climate was right to push cards with weird and wacky rules interactions