I like the idea of it, but it seems very inconstant in playtesting. There should be more discard, far/away doesn't really discard, overdrawing the opponent seems to be very weak as apposed to just full discard. I'm also not sure what deathright shaman does for this deck.Perhaps I'm just inexperienced, but those are my suggestions.

The Shaman is for acceleration and to make use of discarded cards for extra damage. I'd run Mind Rot , but there are better three drops to run in the deck.

How about maybe adding in a few Mind Rot s, as this gets your opponent to discard 2 cards which (if i'm right in sayin) will trigger your Waste Not twice. I would be tempted to replace AEtherize with AetherSpouts as this will slow your opponent down even more.

@BugEye
Mind Rot was an obvious first choice, but the discard spells I have in here are designed to make my opponent discard as much of their hand as possible. I really don't know what I would take out. I think Nighthowler is the card that is easiest to lose, but then I'd only be running 11 creatures. Too few, I think. Rakdos's Return can be used for just a few cards, if I have to, but it has the added benefit of dealing damage. Basically, Mind Rot would need to be either cheaper, or do more to justify.
The reason AEtherize is better, is that returning creatures to hand lets me force the discard on my turn, getting me more zombies. If the opponent puts them on top of their library, my Whispering Madness gets me fewer things. That's how I estimate it, anyway. I'll keep AEtherspouts in mind when I go to FNM. When I play Aetherize, I'll consider how things would be different if it were an Aetherspouts instead.Thanks for your comment.

I would up the land count to something in the area of 24-25, it may seem like it's excessive but you need to ensure that you hit that fourth land or else cards like AEtherize and Whispering Madness are going to sit in your hand forever. I love the idea of Grixis decks, and if you have access to Ashiok, Nightmare Weaver I would find room for them. That Planeswalker is super under-appreciated and wicked cool.

Johnny5 I agree completely about the land. 20 land just is not cutting it. I'll probably remove the Archetype of Imagination s to add more swamps, and maybe switch a Rakdos's Return for another island. I don't know that I agree about running Ashiok, Nightmare Weaver in this deck. It's a well designed planeswalker, and I do like the 3 cost vs the 5 cost of Vess, but Vess has all three abilities that work toward my deck's purposes, it forces discard, it tutors up what I need to draw, and can put all discarded creatures into play under my control. It may be that the 3 mana cost makes all the difference between the two planeswalkers, and of all the games where I drew a Vess, I only cast her once. I'll see if I can borrow some Ashiok's from someone and see how well it works in here. Thanks for the feedback.