Essentially, this list uses Tara, Hannah, and the Hodgepodge Emissary to bury a bunch of nasty short-range bruisers and the Scion of the Void's action lending to unbury them in the middle of the enemy crew on the first turn. Naturally, this is great to use against shooty crews (which will either have to scatter all around the board fairly quickly or get tied up in melee), but not so good against melee crews (which will thank you for closing the distance before turning most of your models into a fine paste)
I had taken a rough stab at this concept around eight months ago, wherein rules misunderstandings were sorted out and some advice on good and bad matchups was given. Since that was eight months ago, I've started a new thread for clarity and to avoid thread-necromancy (this not being that smelly Resser's thread :P). As before, thoughts/advice on the current list would be greatly appreciated.
50 ss Tara (Outcasts) List: Fastball Special v2
Master: Tara (Cache 4); Upgrades - Eternal Journey (1 ss), Knowledge of Eternity (2 ss), Oath Keeper (1 ss).
Henchmen: Scion of the Void (8ss), Hannah (10 ss), Montressor (9 ss); Upgrades - Ancient Tomes (2 ss, Hannah), Brick by Brick (0 ss, Montressor), Fearful Whispers (1 ss, Montressor)
Enforcers: Hodgepodge Emissary (10 ss); Upgrades - Conflux of Nothingness (0 ss)
Minions: Void Wretch (4 ss)
Total: 48 ss, the remaining 2 of which can be saved/spent on upgrades or very cheap models to better suit a given matchup/strategy/scheme.
Basic Play Strategy: Your crew should deploy close to the edge of your deployment zone in a nice cluster within effect range of each other. Except the Void Wretch, who finds a nice piece of cover to hide in for quite likely the remainder of the game. Tara activates first, discards Oath Keeper for Fast and either hits Hannah gently with her sword (to maximize probability of success) or uses Pull the Void (to minimize potential damage) together with a Glimpse the Void trigger to bury Hannah. Next, Tara uses Whispers from Darkness to borrow the buried Hannah's Void Record and buries Montressor. While the SotV could be buried instead at this step, there is a remote possibility that your enemy might try and snipe the SotV across the board on their activation, allowing her to bury herself and saving you a (0) action later (which will be in short supply). Next, Tara uses Pull the Void on the Hodgepodge Emissary to give him Fast. While the extra AP generated by Oath Keeper isn't strictly necessary, it acts as insurance against a Black Joker flip in Tara's activation (which would otherwise remove a model from your initial offensive) by letting you repeat a step, and lets Tara move up the board toward the action a bit quicker if you don't. Finally, Tara uses Eternal Moment to make up for her largely stationary first activation, letting her move up the board later.
Next, the Hodgepodge Emissary uses Into the Maw to bury the remaining Henchman, and moves 15" towards the enemy crew. In the unlikely event that SotV got buried during the enemy's activation in the meantime, he can get an extra 4" of movement by taking A Weary Road. Then, he borrows SotV's The Hollowing to unbury either Hannah or Montressor. I would usually recommend Montressor, as he has more mobility then Hannah for subsequent positioning, a larger threat range, and can stop the enemy crew from scattering by Tossing the Noose. That being said, if the enemy crew has a large number of models in a roughly 10" circle that are squishy enough for Montressor to survive close contact with, you may wish to save his (0) action for Fearful Whispers and mass immobilization by unburying Hannah first instead.
Montressor uses his activation to close the distance further and either trap 2-3 enemy models in base contact or secure and paralyze a key enemy model. Keep in mind Montressor's slight squishyness, and avoid entangling anything he'd be unlikely to survive a round of close combat with. Hannah (if going last), can take the opportunity to hit Montressor's trapped models with a few Horrifying Ghost Censer blasts (synergizing with Montressor's crowd control, Mocking Laughter's penalty to willpower, and Comfort in Fear if you had enough models in range to make it worthwhile) or go after stragglers. Remember to position to allow your second and third models to unbury within about 6" of the Hodgepodge Emissary, so they can get Fast from his Screaming from the Void.
The first model to unbury then uses their (0) action to use The Hollowing and unbury the SotV, who will have taken 4 wounds from lending actions. While Returning Home lets her avoid any enemy action targeting her, you still want to get some use from her this activation and a clever opponent might be able to finish her off with enough indirect damage, so be careful where you put her. Once actually activated, however, she can move with relative impunity (thanks to her aforementioned Returning Home) with a wide range of good possible actions: finishing off weak models trapped by Montressor, tailing stragglers to stop them from scattering too much, drawing cards with The True Path trigger (which, given the potentially resource intensive first few activations, you may be in sore need of), marking a dangerous model with Forgotten to Time for burying later, or even running the objective (should the enemy crew be sufficiently disrupted). Just remember to use The Hollowing to unbury your last Henchman in a good position before going too far out of the way.
The lonesome Void Wretch is mostly there as a safety net for the SotV, healing her, removing adverse conditions, and unburying her so she doesn't get sacrificed at the end of the turn. As such, he'll likely want to stay as far away from trouble as possible, though he could run objectives if the SotV hasn't needed to bury herself and the enemy crew lack the range or mobility to deal with him.
Finally, Tara reactivates and either moves up the board or runs objectives, depending on how well the alpha strike went (While 'Alpha Strike' is a fair bit cooler sounding as a list name, it lacks the cheesy connotations appropriate to this list). Come turn two, the enemy crew has either been largely contained, scattered as much as they can in the course of five activations, and either they or you are in serious trouble, depending on how well they can handle three fairly nasty models appearing in their midst.
List Variations and Matchups: This list has been primarily designed with Guild and Gremlin matchups in mind, due to the likelihood of facing ranged crews and their range of Living models vulnerable to horror duels. While this list can play like a regular-ish Tara crew if the fastball special maneuver would probably get your models stuck out of position or killed, it may not fair quite as well as regular lists.
A respectable portion of Montressor's defense comes from his Terrifying (Living) and his crowd control abilities. If a matchup would likely limit the effectiveness of either of those (fairly likely with Arcanists, Neverborn, or Ressurectionists), substituting another relatively mobile and durable Outcast Henchman (such as Taelor) would probably be a good idea.
While the listed alpha strike ideally has a 31"-35" threat range (3 Emissary moves [3x5"] + large Montressor base [2"] + Montressor's Nimble [4"] + optional Montressor move [4"] + Toss the Noose range [10"]), enough severe or blocking terrain on the table might prevent the Emissary from getting close enough to the enemy deployment zone. In such cases a Freikorps Trapper could be exchanged for every upgrade except Eternal Journey and Ancient Tomes (needed to bury the models efficiently) to deploy up the board and unbury the Henchmen, but doing so makes the list extremely tight on soul stones, vulnerable to an unlucky Black Joker during set up, and much less versatile.
Karina could also be substituted for most of the upgrades to add more Bury/Fast synergy and some more sustainability from summons, but to do so one has to sacrifice 5" of fastball threat range, Tara's Knowledge of Eternity, and either insurance against the Black Joker or Montressor's Fearful Whispers.
A similar list could probably be made for the Ressers (for example, using a buried mercenary Killjoy, Bete Noir, and a suicidal Crooligan. Or just a mercenary Hannah and a not-as suicidal Crooligan), but, again, the Resser's thread would probably be the better place for that.
If you've had the patience to read through that respectably sized wall of text, then again, thoughts/advice would be greatly appreciated.