Remade review, everything gets clearer with more experience:

Coup de Grâce is a funky card and surprisingly, it's pretty good for what ails combat focused characters.

When you do battle with a "Skids" O'Toole or Jenny Barnes or Finn Edwards one thing will probably strike you, routinely making attacks at +6 or better is a challenge and you often need to go even higher to combat harder foes (or harder difficulties) or guarantee overcommitment success from cards like .41 Derringer or Switchblade. All those attacks probably cost money and cards and precious ammo. One annoyance that fighters struggle with uniquely is the "Hard enemy with 1 hp left", do you blow another shot from Chicago Typewriter on it? No gun to finish what you start with Sneak Attack or Backstab? Without proper bonuses you literally stand no chance at killing the bad guy like a might do with just raw .

This is an innate issue that Coup de Grâce fixes. It's a costly fix but a fix still. On one hand the card mechanic can do it, but also the 2 icons might get you there as well.

Coup de Grâce is the card that finishes what you start, it's a niche and the currect class that is queen of niches is of course, .

Worth noting that this card can situationally combo with Quick Thinking (especially in a multiplayer game when you have more chances to commit Quick Thinking outside of turn). If you can use Quick Thinking to get an extra action when it’s not your turn, e.g. during the Mythos phase or during another investigator’s turn, you can use Coup de Grâce without worrying about ending your turn prematurely.

A fun upside: you can combine this with the Chuck Fergus to play it fast & free at the end of your turn. if you’re going to run Chuck, this card goes from “sometimes it’s useful with quick thinking or against aloof enemies“ to "an enemy dies and you draw a card."

I don't find myself a fan of this card. Usually when something is dishing out a single point of damage I am looking to take out those pesky 1 cost enemies like a wil o' wisp or a cultist at a location that I can't afford to fail taking out or will slow me down. But, unlike using something like the Lantern which would remove it at any point in your turn, the Coup de Grâce requires (well not quite requires, but you won't want to do so otherwise) you to do it as your last action in the turn. I could wait until the last action to remove the wisp, but then I would be suffering the rest of the turn from stat reductions until then and if I take something out early in the turn I have lost valuable actions in doing so. Of which, I was likely better off evading and just walking away half the time.

There are circumstances that could arise, but I think this will be the card that sits in your hand waiting for those circumstances to arise that never gets played. You end up walking into a room last action and then take something out and draw a card sure, something like that or you fall short in one attempt or two and something needs a finishing blow, or your left something on one hit point left sure. I would often likely find myself holding this in hand and then just throwing it for the icons because those situations don't show up. That's what I feel like the normal use of the card would be as I play.

The most amazing thing about this card is that 5 point-blank shots to the skull deals only 1 damage. Who wants to pay 2 resources for an effect endowed in every investigator (to attack for 1)? And to top it off, your turn is now over. Terrible.

This card isn't terrible, I have had some fun using it, but it is generally a bit disappointing.

The resource cost of two wouldn't be much for a permanent asset, but for a one shot event it is fairly expensive, compared to the alternative of a skill card which is free. And the restrictions on Coup de Grace are really pretty limiting, unable to be combined with a weapon and usable only as your last action. Lots of times it would just sit in my hand waiting for that perfect moment, while I wished it was a card better suited for the situation I was actually in. The advantage of this card is that it is a totally automatic success, and that is a formidable advantage, the reason why you might consider including the card in your deck. But once I have a character who is set up with enough strength to intentionally enter combat, a skill card like Overpower would do a pretty good job making an attack very likely to hit, while being a lot cheaper and more flexible.

The saving grace of this card is having two strength icons, so it is actually can be used in the same situations as Overpower. But the card draw from overpower is quite a significant bonus, and with the skill bonus being so much more flexible, it is pretty tempting to simplify things by just taking Overpower and skipping this card. In general, I would only put this card in my deck if I had some space and wanted to try something different in my deck construction.