And I'll be in for my own game, obv.
OK, here goes nothing! Editing with my responses to the first three:
1) Graverobber: Well, to start, it's an Expand that only works on action cards. That's sort of gimped, you can no longer expand copper into useful $3 cards (not much of a loss), you can't expand estate into a useful $5 (ok, that's a loss). But you CAN still Graverobber a $5 into a province. So that's something.
However the strength of this seems like it would be in games with lots of trash-for-benefit; if people are trashing useful $4s and $5s to get good stuff, you can steal that right back and topdeck it. But you can't Graverobber Bishopped provinces or anything...
Seems like there's some pretty brutal decks to be made which combo Graverobber with Apprentice or Bishop or Develop; those combos might be tricky to pull off, though, since graverobber is terminal. But I just don't see another use for it. I bet there'll be some nonterminal TfB in Dark Ages that it'll combo perfectly with.
Works with: engines which use trash-for-benefit cards, will be quite powerful in that niche case.
Doesn't work with: most other boards, since it seems like you pretty much have to be able to play the TfB and the Graverobber pretty often for this to be worth it over other powerful $5s. I guess you could have a powerful engine which graverobbers a $5 into a province, and then graverobbers it back on top of the deck? I'm skeptical, since at that point you have to have three $5s in hand to get a province, and, well, a lot of $5s will get you to that point if you have a few of them. Right now seems quite weak, but this may change as the rest of Dark Ages introduces more things it combos with.
2) Poor House.
OK, this looks cute. Great for starting up engines when there's heavy trashing going on: you basically don't have to worry about overtrashing treasures, trash all the treasures you have and pick up one of these with your last copper or terminal silver. Or once you're drawing your whole deck, Mint/Forge/Chapel away all your treasures and buy two of these. It guarantees $4, so you can pick up villages and smithies and cheap terminal silvers with it if you get it early. Great as a money source in treasureless engines. Obviously can combo with things like Vault and SC, though I bet that won't be a particularly common case.
Powerful with: any engine board with strong trashing.
Weak when there's no trashing.
Oh, and it's the best 1-cost card so far by far.
3) Sage: a cantrip which skips curses, coppers, and estates.
Sage/Sea Hag opening. Ouch. Ouch. Ouch.
I bet this will be a popular opening when there's any good second card to open with. Sage/Sea Hag. Sage/Remake. Sage/Workers Village if there's peddlers around. Sage/Moneylender to really clear out all those coppers. Sage/Potion if you're going for scrying pools or apothecaries. Someone will have to do a check for whether sage/potion is better than silver/potion for getting an early familiar. There's probably lots of others, and there'll probably be lots of debates over whether a "Sage/X" opening is better than an "X/X" opening for various 3-cost X, like Swindler or Steward.
Powerful $3, for sure, though it'll lose power as the game goes on. But still, at worst it'll be a cantrip.
4) Feodum. Hmm, an alt-vp costing 4. Could it work in a IW/Workshop rush? Seems like it would, you can pick up enough silvers for it to work. Combos with all the silver gainers around (trader, Jack, Explorer, etc.) Some better than others, but it seems like Bureaucrat-Feodum could be a playable tactic? Might be a trap. Trader/Feodum might be pretty dominant sometimes; if you have more than 3 feodums, tradering a province is a net VP gain. Geronimoo's simulator will probably help in deciding which of the obvious combos work and which don't. In a fast BM game, a consolation prize probably worth 1-2, but in a drawn-out game you'll need to count silvers and see how good it gets.
Obvious combo: Graverobber-Feodum. Trash your Feodum for silvers, then pick it back up. I have this feeling that Throne Room+Graverobber+X is going to be a serious combo which works with a lot of Dark Ages cards as the X
5) Cultist: Well, cultist spam seems like an obvious strategy. It's like a lab which attacks but which can only play other cultists; or, if you're not chaining them, then it's sort of like a Witch (+2 cards, give out a curse). Then when ruins are out, you start trashing your cultists for bigger card bonuses. Combo: Graverobber/Cultist... trash a cultist for a province and draw 3 cards. I think this'll be in competition with Witch for top attack; maybe even better than Witch because you can get them in bulk and not fear collision, and if there's any trashing around then a transition from attack to post-attacking-rebuilding can go much faster because of the +3 cards on trash.
6) Ruined Market: Ruins seem like they'll be a minor incentive to go engine instead of BM and stock up on a few extra villages. The minor bonuses aren't much, but in an engine which has extra actions, they're at least something, whereas in BM+X they're dead draw. And hey, sometimes an engine just needs that +buy when there's none around... I bet there's going to be cases where you want to buy a Ruined Market in a game without other +buy, and it'll feel super cool when it works.
7) Squire: very nice card. At the very least, it's a +1 coin +2 actions village - that's an acceptable village to use for an engine if you need to build one, the +1 coin lets you skip a few treasure buys. And if there's no +buy, then use one of these for a terminal +buy. Those'll be its most common but sort of mundane uses. But in any kingdom with an attack... oh boy. Getting familiars without getting a potion. Chapeling these into a goons. And they even give +buy so you can pick them up in bulk just to trash them.
If there was any doubt that Chapel is the best $2 card, there'll be no more after all of Dark Ages is out. Chapel/Squire opening, if they collide you trash three starting cards and the squire and GAIN A GOONS. Of course, the power of squire will depend directly on the power of attacks in the kingdom - not worth it if the only attack is like spy or something nonspammable like Militia. But with some good attacks, watch out.
Hermit/Madman. Well, obviously, hermit combos with squire, you can use hermits to trash squires. They can trash your starting estates from your discard, but can't trash coppers. Not a thin-your-deck type trasher. But it'll combo with all those things in Dark Ages that need to be trashed. And it gains you, like, silvers or other mediocre cards... or squires! But if you don't buy anything, you gain a madman. Madman is awesome - +2 actions +4 cards if you just draw him in hand, possibly more if you've already started up your engine. But is it really worth not buying anything on a given turn to set up a future turn like that? Maybe. Obviously combos with gainers and cost reducers so you can get stuff without buying it... Dunno, Hermit/Madman on their own seem like they'd be difficult to set up and do anything with without serious help. It'll obviously work with Dark Ages cards where you're okay spending a turn to trash/gain stuff and then you can get a free Madman out of it, but I don't see it being a useful investment in a more standard engine or BM game where you'd rather just buy money or engine components. A turn to buy Hermit, a turn of not buying anything to trash Hermit and gain Madman, to finally get one super-madman turn... slow.
9) RATS. I'm not getting this card at first glance. It doesn't actually decrease your deck size, it just converts cards into rats. you also need another way to trash things to trash the rats, and if you're doing that, why not just get that one in the first place?
I can imagine, like Rats/Apprentice or Rats/Upgrade or Rats/Salvager, but other than that? Well, other than that it is reasonable when you want to have your deck be based on trashing and untrashing things, like some Dark Ages games might be. But won't the rats just flood your deck and take over?
Rats/Scrying Pool might work, having your estates/coppers replaced with rats is just as good as having them trashed. Rats/Forge: forge 2 rats into a province. OK, so rats is going to be a card which works with TFB and only TFB?
10) Pillage/Spoils. OK, tricky. It's three one-shots in one card. One-shot super-powered attack - picking a card to discard from someone's hand is pretty brutal. Then two one-shot golds. Oh, and once you can draw your whole deck, this makes for a brutal pin. I draw my whole deck, throne room one of these and a play graverobber. Basically destroy the other person's hand (no engine potential when you lose 2 cards!), graverobber the thing back into your hand, and spend the spoils from last turn to buy a province or whatever. One-shot money. Pretty nice if you can get that to work.
Seems like it's a powerful card, but would be hard to get to work right.
11) Shelters: Necropolis, Overgrown Estate, Hovel.
These typically won't change the makeup of the game much. Necropolis is the most useful out of all those, but an extra disappearing village won't make or break an engine. I suppose with Hovel you might see some earlier Duchy or Province buys if you have one of these in hand, it's free VP.
But, they'll seriously mess up some TFB early-game. Remake is no longer that good, if you're trashing the 1-cost shelters for 2-cost estates instead of estates for silvers! You'll need another 2-cost card on the board to Remake things into. Same with Upgrade.
Other than that, they won't affect much.
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GOKO SPOILERS:
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The rest of the ruins: Abandoned Mine (+1), Ruined library (+1 card), Ruined Village (+1 action), Survivors (inspect and either discard or put back the top 2 cards of your deck): Eh, they're ok. Less harmful for an engine because you can use them. Just overload on villages and they're not so bad. Still annoying though.
Vagrant: +1 card +1 action, grab the top card of your deck if it's a victory, ruin or curse. It's the new Pearl Diver - marginally useful in engines, but mostly something to buy when you have $2. Sort of combos with deck-inspection, since you can set up the second card to be junk and thus drawn, but you can't build a strategy around it.
Fortress: +1 card, +2 actions, when you trash it it goes back to your hand. Well, it super-combos with any trash-for-benefit. 4 cards with apprentice! 12-points-per-turn golden deck with these and four bishops! Remodel it into a gold and get it back! Trash it with rats and don't lose it! But unless one of those crazy combos is out, it's a standard village for $4. I think it's pretty obvious how it'll be used, it's just a question of which TFB+Fortress are worth building your entire strategy around and which aren't. Bishop, Apprentice - probably yes, Salvager... eh, you need card draw with that, but great if you have an engine anyway. Remodel/Expand/Graverobber probably not. Upgrade maybe, depends on the other $5s. Turns lookout into a cantrip lol. Counters Saboteur and Swindler pretty well. Rats no.
Ironmonger: Well, after you've ironworksed a card into your deck, you can ironmonger it off the top. It's pretty versatile. IF you get too many of them they're just villages - but hey, with sufficient trashing, in a treasureless deck, it's a village! That's cute. In a BM+X game, it's either a peddler which cycles one extra card, or a lab which cycles one extra card, so pretty neat. But with a chance of turning into a village if you get too many.
Overall, I think it will be an often-bought card, probably even overbought. Quite nice to have, not something you can build a deck around, but good support for anything.
Procession: Well combos with Fortress lol. Fortress+Procession gains you a $5 card, draws you 2 cards and puts the Fortress back in your hand. Not bad, but you need a payload, of a good $5 card. Great if there are lots of cheap actions you want to double and get more expensive actions for. Bad if all the worthwhile actions are at one price point. Village/Smithy/[good $5 action]/[good $6 action] is pretty reasonable, in that case procession will probably be a must-buy. For a minion stack, no. Situationally powerful, but I don't think it's THAT much better than Throne Room. (Unless there's a powerful engine made of X-cost components where the payload is a small number of powerful X+1-cost components).
Scavenger:
Well, 2xScavenger 3xStash is literally the "lucky chancellor". Super-powerful, even against cursing, but not against discard attacks. Really Scavenger is pretty nice. I'd open Scavenger/Silver on a lot of boards I think, whatever I was going for. Put your silvers and golds on top, or whichever engine component is rarer. Great for BM+X and engines, but better for BM because with engines you're probably drawing multiple engine components in hand anyway, you need to guarantee that you draw the right combos, not individual cards. Good with expensive actions like King's Court or Expand, make sure you draw them each shuffle. Okay with single-card engines, but why would your HP/Minions be in the discard anyway? So not so great there probably. With some villages it can fish for particular actions from your deck mid-turn, but might take a little too many cards to get it to work and be useful.
Band of Misfits: Great engine grease! A village if you need it, or a smithy if you need it. But it can't be a power $5. Well, I mean it can't imitate a power $5, it probably is one. Great for imitating cards whose utility runs out, like early-game trashers or sub-$5 cursers. Great when you were going to spend $5 for a Village anyway.
Not so great when something you need gets pile-driven. Don't use this to imitate, like, a Caravan or Fishing Village in 3 or 4player.
Works with - engines with limited trashing (where it's hard to match up components). Engines where there's multiple components costing $4 or less. Games which go through multiple distinct 'phases' where different things are necessary. (A bunch of cursing goes on first, then everyone clears out curses/coppers/estates, then you mega-turn, for example - it can be a Young Witch early, a Steward later, then and a Bridge at the end.)
Conflicts with - engine components costing $5 or more, duh. Power $5s. Components that get bought out anyway.
Bandit Camp: If you draw that spoils the same turn, it's roughly "+2 actions, +$3". Like a Festival with the buy exhanged for a coin. If you don't, well, then you got +1 card now and +3, -1 card on some future turn. Not so good then. Pretty nice for a pseudo-treasureless engine. Just buy engine parts, and your Bandit Camps will get you the spoils to play for cash. Similar in power to Festival, Bazaar, the lot.
Count! Ah ah ah! Versatile. Can trash in bulk, saving either 1 or 2 cards to the top of your deck or your discard. Terminal gold.
Probably not THAT great. On-play it can be like Mandarin, but Mandarin's not so good. I mean, it'll be used as a trasher when trashers are needed for Dark Ages... And late-game to save cards for next turn and get a Duchy... It's super-versatile, but all the options aren't that amazing.
Well, maybe 'trash your hand' when you've drawn your whole deck. That's pretty nice.
Altar: Straightforward. It's a $6 workshop which gains $5 cards. Altar/City is probably a combo.
Actually, should probably be compared to university, a little. Without the potion cost, but it costs you your first gold and is terminal.
Works with: Spammable $5s. Festival/Altar/Watchtower? Yes please. City/Procession/Altar/Bridge? Super. Altar/Market... meh. Altar/Highway - super, if you also have +buy somewhere. Like on a $5 card.
Probably not so great in a more standard engine game where there's worthwhile sub-$5 components which you can just buy. Works as a pseudo-+buy if there's no +buy, that's pretty good.
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GENCON SPOILERS
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Armory - gain a card on your deck costing up to $4. Well the set had to have a workshop variant. Slightly better for engine-building, slightly worse for gardens rushing, mostly about the same usage as workshop. Can obviously do crazy things if you have card draw and villages so you can gain and play things same turn, but that's not going to be the dominant use case I think.
Beggar - awesome with Gardens, of course. It's like a gold in hand if you like coppers. Counting House/Beggar might actually be playable straight up. As a reaction... well, counters top-deck junking and trashing attacks, but does not much vs cursing or discard attacks, so... meh on that front.
Catacombs - it's a pretty nice Smithy variant. Will work fine in BM+Catacombs, you might cycle 6 cards per play, or know which 3 you're getting so you don't get stuck at $7 or $5. Works reasonably in an engine deck too. I don't think this will bring us many surprises. The on-trash effect seems like it won't be used much, almost an afterthought.
Counterfeit - treasure that gives +buy, amplifies your existing treasures, and trashes them. Going to be a mega-turn enabler - double-play Banks or HoPs or on even golds/plats. Counterfeit+Plat = Colony. In a more standard engine games, it'll be okay if there's no other source of copper trashing and you want copper-trashing, but not great. In that case it's a moneylender-like effect, Counterfeit+Copper = $3 and trashed copper.
Knights - a trashing attack like that seems pretty powerful. But maybe we should know better given how SAboteur is sort of bad. This gives the opponent a choice of what to trash. They can't gain something instead, but what would they usually be gaining, like, silver? And this gives you a benefit too, so this card won't be saboteur-like bad. But it seems amazing at first and I bet it really, really won't be unless you make a knight engine that plays multiples per turn. And of course, thematically - on boards where this is good, the knights will duel each other and kill each other off. Lovely. But yeah, this will end up middle-of-the-pack on Qvists's list and not on top. Which knight is best to get, of course, will depend on the board; all the benefits are roughly comparable but depend on what you need, sometimes what you really need is a village and sometimes what you really need is +2 cards.
Death Cart - oh wow. +$5? But you need to trash an action card! ...but you can trash a ruins, and it even gives you 2 ruins to trash. Great source of engine cash if you can draw it with a ruins. Great if there's cheap $2 actions, especially if there's a cost reducer around. Or maybe you can use it to trash rats. Yep, Death Cart/Rats, there's a synergy there. And of course ironworks/workshop will love this card, assuming you have the actions and handspace to play them.
Forager - it's a copper-trasher that gives $1... at the cost of trashing a copper from your hand... you can power it up by trashing Silvers, but then you power up your opponent's Foragers too... Not so great a card IMO. Can easily get powered up in forge games or something, or when there's a bunch of different Kingdom treasures that you want to trash for whatever reason (Remodel/Expand?) but even then it takes a while to power up and isn't so powerful even when it does. I mean, it's a nonterminal trasher and sometimes you just need a trasher, so it'll get bought, it won't be a dead card, but... Reminds me of Trade Route and Lookout. Similar cost and power.
Hunting grounds - super-smithy! It'll work for making an engine, the on-trash benefit might be a late-game bonus if you ever have reason to use it. Sort of like Catacombs. BM+Hunting Grounds will be awesome if you happen to draw an early $6, but will be really high variance because if you get stuck at $5 for a while you're just playing BM with nothing. I think despite its cost, it'll be workable for making engines happen, but it'll be high-variance there too. Maybe it'll be best as a kicker with one or two of these to really draw your whole deck, with most of the engine made from cheaper bits.
Rogue - now THERE'S a counter to knights. You trash my cards, I get it back! Or trash yours if there's nothing in the trash. Rogues vs knights, the epic battle. Which is better, which is better. Pretty much the same IMO. Knights are higher variance because of the different benefits - sometimes +1 card/+1 action is better than a +$2, sometimes, +2 actions or +2 cards is definitely better than +$2, but +2 buys is often going to be a lot worse than +2. I look forward to angry debates on this site about whether knights or rogues are better and when, but I think they'll pretty much be equivalent most of the time. I'd judge which to get based on the top knight in the pile.
Storeroom - pretty cute! A cellar AND a secret chamber. But terminal, that's not so powerful. You can cycle your estates... and then any estates you draw you can discard... I mean, I guess you can safely discard all your coppers and try to find your golds. But... it's terminal, so not so amazing for engines, when you sort of want to be able to cellar all your treasures to find that village to match up with your smithy. Gonna float to the bottom of Qvist's lists.
Wandering Minstrel - a Village which also sifts the top of your deck for your actions. A reasonable bonus on a $4 village. Great for engines with low trashing, not so great in trimmed ones, but hey, it's always a village.
Mystic - Well, it's a nonterminal silver for $5. If you wish right it's like a Grand Market without the buy, if you wish wrong it's a nonterminal silver. If you have a little top-deck inspection going on it'll be worth it, otherwise... nah.
Urchin/Mercenary - pretty nice. Get some urchins and some villages, let the urchins turn themselves into Mercenaries which then will do both the deck-trashing and the attack part of your deck, as well as giving you coins. But you gotta be really careful, if you over-trash your mercenaries become dead cards. I think this will be quite powerful when you get it to work, but it really requires sort of weird support - you have to have another engine along with it, basically.
junk dealer: OK, this one shouldn't surprise anyone. +1 card + 1 action +1 coin, trash a card - the perfect peddler variant for Dark Ages. Balanced $5 card, probably good in a lot of situations but especially with cards with on-trash benefits (like, the rest of Dark Ages). Cantrip trashers are powerful regardless, so it'll be good even without that.
Market Square: Great with any fast trashers - ramp up your economy while trashing! Combos with, well, any trasher pretty reasonably, and it's cantrip too. And gives +buy for engines. Versatile and good, except in BM+X.
Rebuild - Transform estates to Duchies, Duchies to Provinces, Provinces to Colonies. Pretty nice. Hard to say how fast this is. I bet pure BM+Rebuild won't be as fast as, like, BM+Smithy, this won't be a BM+X card. But with the appropriate support, you can skip buying green entirely and just Rebuild it.
Hmm. Takes 2 plays to transform an estate to a Province. So if you buy two estates and play 10 rebuilds, you get your 5 provinces. But 10 rebuild plays is a lot. I bet a Rebuild deck is possible, but needs support. Feast, Cellar, Throne Room? Sage? Golem-Rebuild... too expensive probably. And hey, KC/KC/Workshop/Rebuild/Rebuild. Gain 3 provinces! But if you're chaining KCs, you have better things to do than "only" gain 3 provinces.
Niche card.
...in general, Dark Ages REALLY hates BM+X. No BM going on here.