Use Utopia Sprawl, Trace of Abundance, Fertile Ground, and Pentad Prism to ramp into Curse of Misfortunes or Puca's Mischief, locking our opponent out of the game. Almost all our cards have ETB or symmetric effects, so we can freely trade them away for value. Since everything happens to be enchantments, we have a decent toolbox and a huge Sphere of Safety. This deck was inspired by my friend Cory.
Mainboard Discussion
Curse of Misfortunes is a one-card combo. If played turn 3/4, as early as turn 4/5, we get to fetch Overwhelming Splendor followed by Curse of Death's Hold to hard lock creature decks and activated abilities. Alternatives are Curse of Exhaustion to stop some combos or Curse of Echoes to stop spells (esp. counterspells). Once locked, we can fetch Cruel Reality and Curse of Thirst to finish the game as early as the turn Thirst comes down. Remember we get all of this from playing just one card, so we're still playing other removal, locks, and finishers in the meantime (unlike Enduring Ideal, for example).
Puca's Mischief is another one-card "lock" (playable turn 3) which lets us trade away Sprawl, Prism, Spreading Seas, D-Sphere, RIP, curses, and other permanents which are symmetric, take effect upon entering, or don't benefit our opponent (in this deck, that's almost all of them), stealing our opponent's actually useful cards. In fact, we have so many tradeable permanents that we don't need to play bad ones like Nevermore. Furthermore, stealing just one permanent is usually devastating enough to discourage our opponent from playing anything. Since we Time Walk our opponent until they can answer Puca, we have plenty of time to draw a finisher like Misfortune or Demonic Pact.
Misfortune and Puca are played together because they give us 6 "combo" pieces, both want ramp, both benefit from curses (which don't care about controller), and the curses can even be traded away with Puca.
Sphere of Safety is actually our strongest lock, with half our deck being enchantments, singlehandedly stopping most creature decks. We often Idyllic Tutor for this.
Leyline of Sanctity auto-wins against Burn, Pyromancer (left with only 10 spells!), Titan Shift, Storm (game 1), and is still our best way to interact with noncreature/creature-light decks like Death's Shadow, other discard, Jeskai Control, Lantern, Ad Nauseam, etc. Even if it's useless, we can at least trade it for something good. Beware that giving our opponent hexproof prevents us from playing Misfortune, but doesn't prevent an existing Misfortune from attaching more curses (since these don't target).
Runed Halo/Nevermore synergize nicely with Leyline to shut down the alternate win-con that most combo decks have (e.g. Primeval Titan after we stop Valakut, creatures in Burn, etc.). It's also a decent imitation of Leyline by itself, cheaper to tutor for, never a dead card, and one-card combo vs. many decks (e.g. Gifts Ungiven in Storm, Death's Shadow, Slippery Bogle or Gladecover Scout, Prized Amalgam or Bloodghast in Dredge, etc.).
Jace, the Degenerate is back from bannation and (of course) jumping straight into our deck. Jace is especially good at shuffling away curses we accidentally draw (using fetchlands), digging for combo pieces, slowing our opponent down while we set up lock, or just singlehandedly winning the game.
Sideboard Discussion
Pack Rat sometimes comes in and just steals the game, since our opponent will always board out their sweepers and at least some of their removal. It also serves as an orthogonal wincon if our enchantment/prison plan isn't working out. Careful boarding in if opponent has too much removal to board out. Also obviously don't board in if opponent's clock is consistently turn 5-.
Greater Auramancy is so much better than alternatives (e.g. Privileged Position, Heroic Intervention, since we're never holding up two mana) that we have to accept the nonbo with Puca's Mischief. We just die horribly to enchantment removal. Luckily enchantment removal is fairly rare, so we don't have to board in too often.
Curse of Exhaustion is a Rule of Law (fairly common sideboard card that has been used to destroy Storm, Ad Nauseam, Grishoalbrand, Living End, etc. but also hits the newly popular Vengevine-type decks, Bring to Light, Taking Turns, and Eggs now) that can be fetched with Misfortunes. Enough said.
Brain Maggot becomes better after our opponent sideboards out their removal. Maggot is just a painless Thoughtseize that buffs Sphere, shoring up anything we have trouble dealing with, like planeswalkers, permanent removal, noncreature combos, etc.
Notable Exclusions
Demonic Pact slowly gives us 5-for-1, and then we get to Donate it to our opponent to win the game as early as turn 6 (if we play Pact turn 3 and Puca turn 6). Pact can be played with or without Puca because it gives us tons of value, and we're likely to draw into Puca (with Pact's draw 2 + 2 draw steps) or at least a removal spell to get rid of Pact. Note: we must Donate Pact on the third upkeep or remove it that turn, because once the "You lose the game" trigger goes on the stack, we lose even if we remove or Donate Pact in response. Another note: our opponent can avoid playing nonland permanents or kill their own permanents to prevent us from donating Pact and lose. It's definitely a risky card and we want plenty of hard removal (e.g. D-Sphere) to kill Pact in case we don't draw Puca, Puca gets removed, or we can't donate.
Links
Thank you Seth PBKA SaffronOlive for featuring this deck on MTGGoldfish! Also thank you Jeff Hoogland for playing this deck on stream!
$150 (55 tix) budget version available here! Also check out Claw Curse , a more competitive version of this deck.