Read from the left-to-right, top-to-bottom, this is the only enemy whose stat line counts down to 0 one at a time.
4 Fight, 3 Health, 2 Agility, 1 Damage, 0 Horror,
A close second is Lurker in the Dark with its 3>2>1, 1>0 progression (or Stalking Manticore). There's also Roald Ellsworth, Nihilistic Stargazer, and Interstellar Traveler whose top stats count down, but whose bottom stats count up. For the reverse, we have Enthralled Security Guard.
I'm not going to comment on the viability of the card too much, (other then to say that in 4 player especially 1 clue isn't really that significant because you're at best removing one of 4 clues from a location which isn't that high impact) but I've seen a couple comments saying that this card lets you filter the encounter deck. This isn't really true. Sure, if you draw a problematic encounter then you can bin it and not have to worry about one copy of it for the encounter shuffle. But you're also fairly likely to not find any particularly bad encounters and end up removing two of them that would have been relatively easy for your team to deal with and cause you to draw the harder ones sooner. You're not actually filtering your draws, because these are cards that you wouldn't have drawn anyway. It's similar to how discarding cards from your deck doesn't substantially effect your draws aside from having to take a horror from the reshuffle earlier as it means that cards you would have drawn in the middle of the scenario are drawn earlier, and later on in the scenario you'll be drawing cards you otherwise wouldn't have if you didn't discard the cards.
In the end, you're about as likely to discard difficult encounters as you are to cause your team to draw them earlier and more often. Not saying the card is bad or anything, just that "improving your encounter draws" isn't a thing this card really does as it is about as likely to make them worse.
In my opinion, this card shows a problem Fantasy Flight Games has with some of their games, namely Arkham Horror and The Lord of the Rings. In both games, a fairly frequent occurrence is scenarios where there's a binary state; either the players are in state A, or they're in state B. For Dim Carcosa, that binary state is "No sanity remaining;" either you have sanity remaining, or you don't. This in and of itself is not a problem, but the way FFG makes the scenario use the state is.
In any state-based scenario, there are a few questions to consider;
For Dim Carcosa, the answers are relatively simple:
These answers help us to better understand the design of a lot of the cards in the scenario; Dismal Curse helps turn the horror on players into damage, Realm of Madness tears the player's board state to shreds if they have no remaining sanity, and The Final Act serves as 2 Ancient Evils and another encounter card if they have no remaining sanity. All of these serve the goal of discouraging players from running out of sanity, and do so admirably.
What's done less admirably in the scenario, in my opinion, is discouraging players from keeping their sanity. State B is heavily punished, but State A feels barely touched, and the scenario honestly feels like it doesn't push losing your sanity (Going from State A to State B) on you too heavily, the way The Forgotten Age might push the Poisoned weakness, for example. Yes, there's Rotting Remains and The Yellow Sign, but even on top of the starting horror you take, it feels like being pushed over the boundary between the two states is gradual, honestly downright avoidable at times.
Once you are over that line, though, suddenly you have to deal with double Ancient Evils (with surge), a 3-of 5 test in the encounter deck, the potential to be flat out killed before you have the chance to react, and a chaos bag that, on Normal, went from five -2 tokens to four -4s. Add in Hastur's nightmarish mutation of the chaos bag, and you've gone from potential victory to almost-certain defeat. Your friends who still have sanity, meanwhile, are still able to traverse the land of the King, possibly without abnormal threat if they're able to shrug off The Yellow Sign and Rotting Remains.
This is the problem FFG has with binary-state scenarios: they make one state too punishing without including enough that forces the player into that state. You live or die based on which state you're in, and it's surprisingly hard for the game to push you into one.
Fortunately, this is somewhat easily fixable; instead of including so many cards that punish players for being in "the bad state," include a mixture of cards that alternate between punishing the players for being in "the bad state" and pushing the players towards that state, designing an encounter deck that not only tries to keep players down but also has methods of getting them there in the first place. For Dim Carcosa, that might have meant making Dismal Curse push the players towards losing their sanity instead of punishing them for not having any, or making Hastur's frankly game-ending token manipulation apply if you have sanity remaining, incentivizing you to fall deeper under the King's sway. The twin suns of Carcosa might be searing madness into the investigator's minds (personally, I think a lot of the visuals from this cycle would actually look beautiful in real life), but that doesn't mean the designers don't have the tools of reason to help them keep that madness from plaguing their players as well.
Now that Scarlet Keys has been released, Alice has greatly increased in utility.
Her biggest shortcoming, aside from cost, is that discovering clues generally provokes attacks from enemies, pigeonholing her as an expensive supplemental damage asset to an evasion/investigation build in the wrong color.
With Keys, however, we have to contend with Concealed cards. Concealed cards normally eat a fight/evade/investigate action to reveal, but Alice effectively doubles your action economy by providing a testless reveal once per round after gaining a clue. Roland, Joe, Rex and Vincent can combine with Research Notes and the new clue-dropping cards to have free reveals on tap.
For Rogues this card is Eon Chart but the action has to be an evade, and in exchange you get +1 to the test (helpful for succeed by X cards) and it takes up an arcane slot instead of an Accessory. For Rogues that plan on doing a bit of evading, (and that's a lot of them) this card IMO is actually just better than Eon Chart (1) because it gives you a boost and it uses a MUCH less contested slot. The evade restriction isn't even that bad, because usually turns where you have to evade are ones where you want an extra action anyway. IMO a sleeper hit card from Edge, at least for Rogues.