First, whenever a creature you control dies, each opponent has to exile a creature of their own--this reminds me of a card like Grave Pact, only better because the casting cost is two Black versus three Black and exiling is better than sacrificing
Magic: The Gathering s newly-released Final Fantasy Universes Beyond set has sent me off the deep end
There are also a bunch of other designs for double-faced cards in the set, including sidequests, characters that transform into their summons (so they have saga creatures on their back face), and even a pair of characters that can meld together
But considering her cost and uninkability, you really need to get max value out of her to make her worth running
Then it's a mana sink for 7 mana to Giant Growth and trample-ify a dork you can target
In Modern I think the RG Prowess deck is slightly behind the URx version (mostly because theres no such a card as Preordain)