Disclaimer: This deck is a thought experiment. It has, as of right now, never been tested. While it works in theory, the reality of the matter could be quite different. Play at your own risk.
When delirium first came out, I, like may, were not particularly excited. For the most part, there was little redeemable about them, at least at first glance. At least, not compared to madness cards.
This deck was created as a thought experiment, to see if it is possible to make a deck that runs on delirium mechanics which actually works. In the process of making this, I noticed that if one is able to get delirium active as early as possible, some delirium cards are actually pretty good, and have comparatively cheaper mana costs than cards without delirium but with similar stats.
The idea here is to activate delirium early through control of the graveyard. Cards like Traveler's Amulet and Armillary Sphere allow you to get an artifact into the graveyard early, and some extra lands as a bonus. Cards such as Desolate Lighthouse, Call the Bloodline, and Bonded Fetch allow you to force certain types of cards to hit the graveyard, as well as to activate Madness. Viscera Dragger can get you a creature card into your graveyard by turn 2, if you can't get one in your graveyard any other way, and can later be Unearthed cheaply.
As for actual delirium cards, I've included the Thraben Foulbloods. 4/3 with menace, for only converted mana cost 3? Yes please. Invasive Surgery was also included as a cheap counterspell that can tear apart enemy decks easily, depending on what you counter with them. Gibbering Fiends help boost your damage output to opponents for a low cost. And Strange Augmentation can give any creature +3/+3 for the low cost of 1 black mana.
Additionally, there are various cards included to retrieve stuff from your graveyard that isn't necessary for maintaining delirium. Mortuary Mire and Academy Ruin can retrieve creatures and artifacts respectively, while Grave Scrabbler can dig up more creatures. This is useful, because this deck will have you discarding large portions of your hand.
Your graveyard will also be powering your deck up in ways besides delirium. Crypt of Agadeem should provide plenty of black mana as you should need as long as you keep your graveyard well fed with creatures. Liliana's Elite gains +1/+1 for the same. And Bonehoard not only uses your graveyard for power, but the graveyard of all opponents.
Hopefully this deck will prove as useful in play as it does in theory.
