Maybe Sultai would be better, since [scryfall]Kiora, Master of the Depths[/scryfall] could be really great here, but I think this should be more aggressive, although I’m not quite sure of the right build, but the reasons I’m even talking about this are plentiful in EMN.
The aggressive build:
Here we don’t use our resources to get to delirium. If it happens, its good, but I’m going to rely wholly on [scryfall]Grim Flayer[/scryfall], [scryfall]Mindwrack Demon[/scryfall] and naturally using our cards here.
[deck]
[creatures]
4 Gnarlwood Dryad
4 Grim Flayer
4 Deathcap Cultivator
2 Moldgraf Scavenger
4 Mindwrack Demon
[/creatures]
[spells]
4 Autumnal Gloom
4 Dead Weight
4 Grasp of Darkness
2 Ultimate Price
2 Reave Soul
4 Traverse the Ulvenwald
[/spells]
[lands]
4 Llanowar Wastes
4 Evolving Wilds
4 Hissing Quagmire
6 Swamp
4 Forest
[/lands]
[/deck]
Admittedly, some of these cards are pretty out there and one could probably find better variants (I could see [scryfall]Prey Upon[/scryfall] for example in lieu of [scryfall]Reave Soul[/scryfall]), but the deck does require a critical mass of different types of cards.
… and more midrange version.
[deck]
[creatures]
4 Grim Flayer
4 Deathcap Cultivator
4 Kindly Stranger
4 Mindwrack Demon
2 The Gitrog Monster
[/creatures]
[spells]
3 Liliana, the Last Hope
4 Dead Weight
4 Grasp of Darkness
4 Reave Soul
4 Traverse the Ulvenwald
[/spells]
[lands]
4 Llanowar Wastes
4 Evolving Wilds
4 Hissing Quagmire
7 Swamp
4 Forest
[/lands]
[/deck]
In the current metagame, even stuff like [scryfall]Tooth Collector[/scryfall] and [scryfall]Obsessive Skinner[/scryfall] (with [scryfall]Grim Flayer[/scryfall]) could maybe work here. [scryfall]To the Slaughter[/scryfall] is pretty must for the sideboard, as well.
I like the looks of that midrange deck a whole heckuva lot.
Thinking on it more, I think my G/B Delirium list might look something more like this:
3 Gnarlwood Dryad
4 Grim Flayer
4 Deathcap Cultivator
2 Moldgraf Scavenger
2 Nissa, Vastwood Seer
4 Mindwrack Demon
3 Ishkanah, Grafwidow
4 Liliana, the Last Hope
3 Ruinous Path
4 Grasp of Darkness
3 Dead Weight
4 Evolving Wilds
2 Blighted Fen
4 Hissing Quagmire
4 Llanowar Wastes
6 Swamp
4 Forest
I like having 11 one-drops in a deck (8 tap lands, 3 Gnarlwood Dryads). I feel like the nut play for the deck is Grim Flayer into Liliana into Mindwrack Demon, so having 4 of each seems optimal. Ishkanah is a huge payoff for Delirium plus Avacyn insurance. The removal has varied card types, and there are six lands that can be sacrificed to toss in the yard.
Nissa, Vastwood Seer is the most speculative card in the list, I think. Maybe she should be a couple of Kindly Strangers instead…