Listen. I just want to cast Emrakul, the Promised End. So mission accomplished there, WotC. I would have preferred to have some better enablers for delirium, though there are some serviceable tools. These seem to be the best new enablers with regard to churning your library into your graveyard at a high enough velocity to matter:
It's ironic that Liliana looks to be among the best ways to set up Emrakul, though her -2 is clearly a delirium enabler and her +1 helps to enable attacks with Grim Flayer. Given that the enablers are a little shy of ideal and that delirium forces us to play a mix of different card types, I can basically guarantee that we won't see the best delirium build week one, though I think there is something here.
The game plan is simple. You get on the board turn two in somewhat aggressive fashion, and then start trying to set up delirium. Your two drops all scale well into the mid game, and then you build up to a game-breaking Emrakul. One issue with this build is that there is no way to discard Emrakul if you draw it, which makes playing a bunch of copies awkward. As such, I have included two copies of Traverse the Ulvenwald to make Emrakul more available, though only two copies as Traverse is pretty terrible without delirium and getting Traverse flooded could be just as bad as getting Emrakul flooded. One nice thing about the deck, is that if Emrakul ends up in the graveyard, both Liliana and Grapple with the Past can get her back.
I imagine that somebody smarter than me will put together something wild and less forced than this build, though this looks like a solid starting point for a week one deck. The deck both has the potential to play aggressively and to play longer games with subtle flexibility and scalability of the cards, which leaves a lot to like about this deck.