GY Self-Harm Control (DLC helpful, but not required)
This deck has been absolutely carrying me on ladder. Despite me hitting myself in the face constantly with Soul Pact, Altars and Doomsday, it has enough sustain to outlast most Burn decks.
In the early game, mulligan HARD for your Altar of Souls. It is your source of early collectors/board presence. Storyteller can be an option in that respect, but I don't like getting sub-optimal value out of it by foregoing the heal. Your first 3 turns should be spent building Deserts next to your wells, and nothing else. Once you have 3, plop down an Altar, start hitting yourself and summon your lovely Shadows. Guard your Altars jealously, for they are your main source of self-harm and board presence. Every Slaughtering Shadow you put down requires an answer from your opponent. That resource is usually a whole card (either a creature your opponent trades into them or a piece of removal), so you can start out-valuing your opponent card-for-card very early on.
Once your 3 Deserts are built, keep building Lands close to your well. Don't extend too much, it's not necessary. Always keep a desert clear for a fresh Slaughtering Shadow. Build your 2 Forests at your own pace (if your opponent isn't being aggressive, you can hold off on them, but one Forest is helpful early on for Faeria generation via Weeping Idol) for the Wild Avengers you'll be bringing to the party in the mid-late game. One or Two Avengers should be all you need on defense, assuming you've been beefing them up by hitting yourself in the face as instructed. Honestly, your Lands are almost as important as Faeria at this stage in the game, because they will most often be full, and you have cards to play. It's not uncommon for me to build a single Forest and then Prairies for a turn or two just so I can play more Structures while still letting all my Shadows can move around. That's another thing: Structure placement is hard to judge without some experience. Just try not to box your own creatures in or hamper their movement by placing them carelessly. Most of the time I settle for one of each, nuzzled up right against my face.
In the late game, your push begins. If you don't have Banon, you may have to start pushing a bit earlier than is optimal. Build lands close to your opponent by utilizing whatever Dash creatures you have left, and start pressuring your opponent with Shadows, your remaining Wild Avengers, and/or Radiance. Your opponent shouldn't have very many ways to remove them at this point, and will eventually be overrun. If you have Banon, pop him when you're almost out of cards, and get 10 extras your opponent will have to deal with. This deck only runs 7 Creatures, so Banon is consistent enough to see play often. I'd go so far as to mulligan for him just so you don't end up milling him by accident, or drawing him at an inopportune time.
Doomsday is the only card I feel needs justifying in this list, but trust me: Doomsday saves lives (lol). When your board is almost empty, your opponent will start pushing, and is likely to overextend. When his Faeria reserves are empty and his board is full, pop this, blow everything up, watch your opponent spend 20 seconds in confused shock before he ends his turn, refill your Faeria with Soul Pact, refill your board with your cheap Structures and Shadows, heal up if needed, and laugh all the way to the bank. Nobody expects this card, and for that they shall be punished.
In typical self-harm decks, it is customary to run things like Shaytan Demons and Annoying Gnats for more constant face-punching. Between you and me, I hate those cards. Shaytan Demons will often overstay their welcome with our passive playstyle, and require your own resources to remove when you can't take the pressure anymore. Gnats have the same problem, but worse. They're useless, you can't get rid of them, and most opponents will RELISH beating them down repeatedly while you watch your life total fade away while not being able to do anything about it. This deck packs major sustain, but the potential damage you can take from Gnats and Shaytan Demons is infinite. Key takeaway: It's important to be able to punch yourself in the face, but it's also important to be able to STOP.