It's worth noting this is pretty good in the hands of Sefina Rousseau and Dexter Drake, particularly when running any of the hybrid Mystic events out of The Dream Eaters cycle: Spectral Razor, Ethereal Form, and Read the Signs.

These events test the base // of the associated Fight, Evade, and Investigate actions, adding your Will on top of them. With the Eye modifying that base, this lets Sefina and Drake test at 9 and 10, respectively, when using these events.

Both also have access to some methods for adding to the chaos bag (ex. Faustian Bargain) and a strong temptation to run Leo as an ally for bonus actions, making occasional the trigger appealing to them.

Just wanted to take a moment to appreciate how rarely this card screws you over. So often it spawns on a location that's already out of clues, or had none to begin with, or even already had a copy of fog on it, so does absolutely nothing. The only problem with that is that it stays out of the deck so it's not around to provide you with any more dead draws in the mythos phase, Its worst case scenarios are blocking a high shroud victory point location, and even then it's about worth a perception or flashlight charge. Adds +2 difficulty to something the seeker is already doing, and doesn't even block you from picking a clue.

I suppose it's a lot worse in higher difficulty levels, and it does block the strategy of flashlighting a location down to 0 shroud. But even in those scenarios, you have all the methods for picking up testless clues that you can just save for when this gets attached to a location.

Overall, I just can't think of any treachery that's shown up in a nail-biting mythos phase where certain cards will just force a loss, that gives as great a sigh of relief when it shows up instead of those. Though perhaps that's just because it's in so many levels.

Another flavorful signature Weakness. Looking at the two elements, the effect and the discard condition, we get:

The effect: Tommy likes Assets, and he likes putting damage and horror on them. This card requires the discipline to use those Assets carefully, so you only lose one or two. It's best if they are cheap (hello Cherished Keepsake and Leather Coat). You might not want to play Agency Backup until you've already drawn this, but Tommy's weakness and his strength is that his draw is terrible, and you may very well go several scenarios without seeing this particular problem. Tommy's access to 0-2 lets you pack Resourceful and Scrounge for Supplies to get the discarded cards back into your hand.

The discard condition: You draw it and either pay its cost or shuffle it back in. A rookie move, you might say.

Taken together, this is a below average signature weakness, unlikely to inconvenience Tommy too much in most scenarios and will almost never be the main reason you lose a scenario.

A delightfully flavorful signature Weakness. Looking at the two elements, the effect and the discard condition, we get:

The effect: This only punishes Ursula if she doesn't do what she loves to do. Good counter-cards to this are Pathfinder, Fieldwork, and, in a pinch, Shortcut. Either of the Esoteric Atlases or The Truth Beckons can also help, along with the usual suite of tools for boosting investigate tests. Seeking Answers can let you target a low-Shroud (or empty) location and still grab clues. As the difficulty level goes up, failure becomes more likely, so Ursula may pack some horror-soak allies, maybe an Art Student or, if you are using an Atlas, the Eldritch Sophist, or invest in some Logical Reasoning.

The discard condition: You don't. You either keep moving and succeeding at investigations (note testless clue-getting won't help; you have to investigate (although you can do it at a location with no clues)), or you take 2 horror and shuffle it back into your deck to strike again. Ursula doesn't really favor a high-draw strategy.

Taken together, this is a below average signature weakness, maybe average in a scenario with a cramped map and a lot of enemies or at high difficulties.

Another "pick your poison" signature Weakness. Looking at the two elements, the effect and the discard condition, we get:

The effect: Leo loves allies, and he loves using them up. The worst case is if you get caught with a pricey or critical ally out (say Leo De Luca or Agency Backup) out and nothing in your hand, but Leo loves to cart around a lot of allies, so this is less likely for him than other investigators. He ought to have one of his meat shields ready to sacrifice. Charisma and a few lower-cost allies is a buffer. Guard Dog, Hired Muscle, or Treasure Hunter are cheap to play, have useful abilities, and synergize with Mitch Brown should you find him, and a "big money Leo" can easily pay the "drip insurance" cost for the "pay as you go" allies. Probably the saddest thing is that this card won't feed Leo's beloved Decorated Skull.

The discard condition: You draw it and either pay its cost or shuffle it back in. Pretty simple.

All in all, this is a way below average signature weakness, unlikely to cause even a significant tempo hit, much less tank a scenario.