Blue/Black storm based on Tendrils of Agony, Brain Freeze, and Bloodchief Ascension as primary win cons. Idea is to begin with quick casts of Tendrils of Agony, Brain Freeze, knowing that you will likely draw into more, or into Snapcaster Mage to recur out of graveyard. Baral, Chief of Compliance is a staple for reducing casting cost of sorcery spells.
Known interactions:
Bloodchief Ascension with three counters + Brain Freeze to mill for death via lifeloss
Necropotence, Yawgmoth's Bargain, Bolas's Citadel, or Ad Nauseam + Tendrils of Agony (to gain back lifeloss from drawing cards).
Tendrils of Agony, Brain Freeze, or Mind's Desire + Remand, to draw cards and put original spell back in your hand.
Snapcaster Mage, or Exclusion Mage + Shrieking Drake or Cavern Harpy, to continue to bounce mages for repeated effect of ETB ability. Can do same with Baleful Strix for card draw.
Shrieking Drake to bounce itself multiple times in order to ramp storm count. (also put this card in becuase Shriekio... lol)
Necropotence, Bolas's Citadel is essentially a lock and alternate wincon. Can rifle through entire library until you can cast Tendrils and get your life back, rinse, repeat. Get ready to watch opponent's scoop when you do this.
Creeping Tar Pit, Cavern Harpy to ramp up Bloodchief Ascension
Baral's Expertise to bounce Shrieking Drake, or your other ETB buddies if they are locked. Or to bounce opponents shit in a bind. Then cast Tendrils of Agony for free.
Dark Ritual + Ad Nauseam into a Tendrils of Agony - make sure you have the mana to cast both.
Brainstorm for a whole bunch of reasons, but to put cards on top of library to avoid discard/exile effects such as surgiacal extraction.
Brain Freeze against Scheming Symmetry - do not hesitate to burn this card early to prevent opponents from getting their tutored card. You will be able to recur this from graveyard, draw another, or pivor to Tendrils of Agony as your alternate wincon.
One major weakness of deck is to lose your two wincons via Test of Talents, surgiacal extraction, etc.. so you have to stay mindful of opponent's board state. Its ok to discard them, because you can recur via snapcaster, but you dont want them exiled. Also, do not be afraid to use your life early to draw into your heavy hitters. You need be popping by turn 6-7 at the latest, otherwise your deck could stall, in which case you are relying on bounce, and creatures for damage - not ideal. Playtest and see what turn you are typically doing the heavy mill/damage. I found that by turn 7-9 I was able to wincon (and this is without allies bumping up storm counts)...
I purposefully left cards like Ruin Crab, and Erayo, Soratami Ascendant
out because former gets heavy play already and I like a different mill flavor, and the latter I am starting to feel is just gay and not fun to win with. But if you feel the deck isnt doing what it should, you could always implement these in place of Ad Nauseam, and maybe one Exclusion Mage type creature.
