I am a firm believer that this is the worst card in the game as of 2020. Sure, Henry Wan's ability is usually awful, at least he is 0 exp and he can soak for you. The Springfield M1903 is rightfully ridiculed but with support it can be a worthwile janky weapon. Book of Shadows (1) is slow, clunky, expensive and just feels bad to play. At least the 3 exp version gives you an arcane slot, which is somewhat useful for most decks that rely on spell assets, and it adds charges for no continuous money sink. And mind you, the upgraded version rarely sees play. So that tells you enough.

Absolutely awful.

As far as weaknesses go, Tony's Quarry is on the mild side. 4 fight would be an issue for many investigators, but Tony fights at 5 right out of the gate and often goes way beyond that. 3 health is pretty average and means that most set-up investigators can take care of this monster in 2 or even 1 action(s). An evade of 1 is laughable and 1 damage is standard. 2 horror is a bit scary since Tony has low sanity but as he can reasonably kill this in 1 turn, that often won't be an issue.

The biggest problem with this creature is that it spawns with a doom on it. That, admittedly, is pretty bad. Worst case, you draw your weakness with not enough time to go hunt it, and it costs you AND your fellow investigators an entire turn by prematurely advancing the act. Also, depending on the scenario, "furthest away from you" could mean in a place you can't reasonably get to.

However, since TQ gets a (free) bounty on it, you will have a bit more leeway in going after it, since you can engage or fight it for free. This also means that killing it gives you a free resource for your trouble. And if the act was about to advance anyway, this is essentially a monster that doesn't do anything beyond camp a location.

All these things considered, I think this signature weakness is not one of the weakest in the game, but it isn't far off. I would be more concerned with Tony's sanity and low willpower if you were to play him!

So Dexter is the only player card that has a May effect that occurs before a Then effect, so now we enter a curious situation, does choosing "no" on a may effect not count as resolving the effect in full. So do you only draw if you return a card to your hard, or do you only draw if you have an asset to return. (and then choose to return it or not)

Yog leads me to believe choosing 0 still leads to the then effect triggers, the effect resolved successfully, you just choose a minimal value.

mild spoilers, but i'm trying to be subtle

Its a niche case but there could be some utility in one of the scenarios. There is a tricky scenario where some locations get discarded in predictible ways (its towards the end of a cycle)... and it says "when a location is discarded, move each investigator and each enemy at that location to 'location x'". If you know when the location will be discarded, you can get some pretty strong monsters discarded along with their location.

Again, pretty niche. I agree its probably got a bit of a revival with Luke Robinson, but other than that i've never found the space in my deck.

nobody has mentioned Minh Thi Phan, who can set up into a "barricade minh" mode where she helps everyone else with skill tests all around the place. She's not invulnerable but its awesome if her random weakness is The Thing That Follows. :-)

So seems like a nice card that can help dealing with lots of damage, I've got three questions and my thoughts on the answers:

Q1) Does it count as "healing" for Carolyn Fern? Carolyn Fern. Clearly its useful for her to more conveniently heal others and get the resources herself, or remove the pain from others when a timing issue is criticial. But... i don't think this counts as "healing" when it comes to triggering her reaction ability, does it? I think it deliberately doesn't use the word heal, you are moving the hurt. It means she can take the horror off somebody close to defeat, but to get the extra resource from healing, she then has to heal herself (or Peter Sylvestre!)

A1) I think not.

Q2) If you have multiple Solemn Vows in play, can you trigger them all at the same time. (say you have some Fine Clothes, can another investigator with two solemn vows trigger them both to do 1 damage and 1 horror to the Fine Clothes, or would the Fine Clothes be defeated after the first trigger?

A2) I think yes you can.

Q3) In conjunction with a cancelling card like Perseverance, can you move the damage/horror from somebody and then stop the damage transferring across to you? Particularly more relevant if you have all three Solemn Vows out at the same time and can cancel 3 damage with Perseverance or Devil's Luck

A3) So long as the effect says you are cancelling the "horror" or "damage", and not the cancelling it being assigned. (because then you would be cancelling the move, so the original investigator would keep it?)