Magma Spray is cheap, efficient, and seems like just the right spell for the job
[26] Players expand their card library for deck construction through booster packs, which have a random distribution of cards from a specific Magic set and are defined by rarity
Having your buffs be card-neutral keeps your hand full and your interaction at the ready, and you wont stall out if your big tough creature gets zapped
In fact, its probably more useful to think of the archetype as Grixis Delirium and view the individual madness spells or graveyard payoffs as interchangeable tools that your discard engine can utilize
Many quintessential Treasure cards are red
Vorinclex, Monstrous Raider Counter doublers are very effective in Magic, so having Vorinclex, Monstrous Raider readily available in the command zone is very powerful