Solitude!

I'd like to preface this by saying:
Solitude (and Solitude in itself, really) is a deck that probably won't get you climbing many ranks. I can get a 60ish wr with it, but I havent tested it in any high leagues nor will I probably ever because I'm contempt with silver. That being said, its an interesting combo! The basis of the combo is that you get one of the following card combinations after controlling long enough to the point where enemy player has 7-10 units/spells in their graveyard.

1: 1x Black Iron Manacles and 2x Solitude (in that order)
2: 2x Black Iron Manacles and 1x Solitude (also in that order)
3: 3-4x Solitude

Now, lets discuss how we get there. Well, Harsh Rule can do that if the enemy plays enough units, as well as enough Slay targets. But, the real kicker is Fallen Oni which fits into our control subarchetype nicely as well as being able to be fetched by Shadowlands Guide and Crownwatch Press-Gang and revived by Dark Return. So, now you know the combo, so lets go down the list and examine all cards and notable exclusions.

(before we continue, though, I'd like to note this deck is based off of Run of the Mill and props to Illuminum for providing a base combo and a pretty goofy deck to toy around with. Cards that differ in our decks will be explained.)

Skipping past Oni and Return which we already talked about, Family Charter serves as useful card draw and Dreamsnatcher is a card that helps you counter aggressive decks, sits at a low low 2 mana, and has an ultimate that (sadly) gets off about once every 30 games.

Exclusion: Torch is a card that, unfortunately, just doesn't have the usefulness of Slay, and, since we're never short on mana because of scarce card draw, it usually doesn't serve a purpose.

Scheme is a card I found more useful than Quarry since we're a combo deck that naturally wants to fetch combo pieces.

Exclusion: This seems a good time to mention some cards you might feel are missing from this deck.
Cat Burglar, Devastating Setback, Prickly Grenadin, Callous Survivalist, Treachery and Overwinder all don't make it (despite discarding) because they are unreliable and can sometimes not even have effects, while lacking the negligible cost Sabotage has. You may very well want to use treachery instead of sabotage, but I could never see a situation where is better on turn two and/or as a topdeck.

In Cold Blood doesn't make it because we really dont want to lose our J influence.
Voprex, the Great Ruin doesn't make it because he's overcosted for a bad effect.
Vara, Fate-Touched doesn't make it because she's overcosted and also needs you to hold/draw a shadow minion to proc her, even though she can cause chain reactions.
Nametaker is a lovely weapon that almost always has an effect, but by turn 8+, it's usually a bad one. I could see another deck running Throne Warden for a sort of armory-solitude, but that's not what we're doing. Azindel's Gift has a stronger effect for 1 less.

For more information, feel free to visit Illuminum's deck (Run of the Mill if you forgot). It explains better than I can what mill is. Have fun!

*Edit* Forgot to mention, Seek Power isn't here because it's an awful topdeck and we don't run any particularly influence-heavy cards.

**EDIT** Set 4 is here! Spitefeeder is a particularly good card, essentially doubling the effect of what the Fallen Oni did before. Some choice cards like Lethrai Provocateur just barely made the deck, but with the addition of markets, most combo decks are now way easier to pull off. Cheers!