While equipped to a creature, it essentially serves as a localized version of Drivnod, Carnage Dominus for that creature, doubling any of its effects that trigger when a creature dies
Alongside some strong removal (two good fight spells, and a good common exiling in Shoot Down), it makes Green a solid color in the format
Of course, there are still a few hoops to jump through, such as having your own creatures to help fuel this mind flayers machinations, but a steady supply of helpers thanks to cards like Sower of Temptation, Beguiler of Wills, and Ghoulcaller Gisa, you wont find yourself wanting
This is somewhat comparable to the recent one-off serialized cards that appeared in Aetherdrift and Tarkir: Dragonstorm
If youve got them, the full suite of fetch lands and shock lands are a lock