Convoke your Graveyard (Pauper)

Use a huge mashup of keywords and card types to put out cheap large threats. In the early game deploy some number of Phyrexian Walker and Ornithopter (treating them like fast mana/lands), then use convoke to drop 3/3s and 3/4 for free and/or 1 mana on your first few turns. Your opponent will probably counter with the 1 mana instant speed stone rains you gave him (cough cough lightning bolt) but you can follow up as he fills your graveyard with Moldgraf Scavenger, Putrid Leech, and Moldervine Cloak with support from Vessel of Nascency to help make sure they stay turned on.

I've found this deck wants 2ish one mana creatures to help with convoke costs early, and Nimble Mongoose is a great option, as he has the side benefit of being a 3/3 very late in the game, and the Shroud helps keep him around. Werebear is an easy flex spot that also helps early with mana acceleration and late as a beater if you do ever hit threshold.

Costly plunder and Bone Splinters will put an instant/sorcery and an artifact creature into your graveyard before resolving, while drawing you all the cards or removing a threat, doing a lot of the work to keep delirium online all on their own. Macabre Waltz can also do this if you have an ornithopter or phyrexian walker to discard from your hand.

I have no idea if this is serious trash or not, but I think if there ever was a delirium deck waiting to be made, it would look something like this. There are 6+ permanents of every card type outside of tribal that can be put into the graveyard to help ensure that delirium sticks over the course of the game.