Well, barring any new challengers, "That shit that make your soul burn slow" looks like the winner, and it continues the odd theme of using rap lyrics.
Anyway, I've been thinking about
this Blogatog post from over a week ago.
bokketoartandgames asked: In hindsight, is it a mistake that one of the most powerful mechanics in Standard, Delirium, and the deck built around it are based completely on the contents of your graveyard, and the only graveyard removal spells are single target?
There’s a method to our madness which I will explain when all the relevant factors are public. Just keep asking and at some point next year, I’ll answer.
From the theme alone, it was pretty likely that Amonkhet would have graveyard-based cards, but I hadn't given much thought to it. Now, I'm guessing they're experimenting with having two different kinds of graveyard themes in the same Standard. I have to imagine that they didn't include graveyard exiling in Standard to create a contrast with when there are tons, but how can a bunch of graveyard exiling be part of a theme? That brought me to the idea of "grave wars", where you and your opponent are both trying to build up your graveyard and stop the other.
One possible implementation of this could be "grave robbing" like this:
Pyramid Raider - 3B
Creature - Human Rogue
Menace
Whenever Pyramid Raider deals combat damage to a player, exile up to two target cards from that player's graveyard and put the top two cards of your library into your graveyard.
2/2
The set will have a lot of card that do stuff from the graveyard, though like Kozilek's Return, they will exile themselves after use. Perhaps we'll also straight up get flashback.