I used to have a Madness-focused Five Color deck that clocked in at 250 cards

Benevolent Blessing Blazing Firesinger Blessing Blessing of Belzenlok Blessing of Frost Blessing of Leeches Blessing of the Nephilim Blessings of Nature Builder's Blessing Callidus Assassin Campsite Cuisine Central Elevator // Promising Stairs Central Elevator // Promising Stairs Chain Assassination Chaplain's Blessing Cho-Manno's Blessing Cleansing Cleansing Beam Cleansing Meditation Cleansing Nova Cleansing Ray Cleansing Screech Cleansing Wildfire Closing Statement Collapsing Borders Collective Blessing Conclave's Blessing Consuming Sinkhole Convulsing Licid Crocodile of the Crossing Cylian Sunsinger Demonic Rising Descend upon the Sinful Disinformation Campaign Disintegrate Dispersing Orb Doc Ock, Sinister Scientist Dowsing Dagger Dowsing Device Dowsing Shaman Drowsing Tyrannodon Eiganjo Uprising Elemental Uprising Ent-Draught Basin Enterprising Scallywag Evercoat Ursine Explosive Singularity Extricator of Sin Eye of Singularity Eyeblight Assassin Farid, Enterprising Salvager

[4] Dice, counters, card sleeves, or play mats may be used to complement gameplay
Why its a contender: It is the benchmark for efficiency in damage spells
The draw advantage this card will bring to black decks may take a few of the competitive ones over the top
At each of your upkeeps, you can put counters on up to three target noncreature artifacts, meaning those 1/1s will keep getting bigger and bigger as you animate them later