Not gonna lie, this looks like hot garbage, but I want to write a review in the hope that someone proves me wrong.

This costs 2 resources and an Action to give you the ability to make a test that makes an enemy not bother the party until the end of the round, so I see it as very similar to Mists of R'lyeh. Obviously, there are quite some differences:

• Different class
• Doesn't use charges and is slotless
• Parley instead of Evade
• No bonus movement (and no drawback for the scary tokens)
• Non-Elite enemies only, but can be used on enemies not engaged with you
• Test against printed health instead of evade value
• Aloof instead of exhaust if successful

Let's start with the class. While Mystics like to use on each and every test, it's one of the most common weaknesses of Rogues all around. In fact, every single green 'gator so far has an equal or higher , so why would they bother. Some of the outside-class 'gators that can take this have stats better suited for it, but Pete, Jim and Zoey have way better things to do with their limited out-of-class slots, while Leo Anderson has the means to deal with enemies in a more definitive way.
Dexter might consider this in order to have different options to play with his ability, but that comes with the age old question "why pick an Evade spell when I can pick a Fight one", especially since being a main-class Mystic means he has other options if he wants some way to deal with enemies while building as a cluever (like Mists of R'lyeh itself). The lack of charges is also kind of an anti-synergy for him, since he likes to have expended assets to throw away.
For Parallel Daisy this has the arguable advantage of being a slotless tome, thus bringing with it a stat boost and a semi-reliable way to deal with enemies, does she have the deckspace for it, though?

Now, clearly, this being a parley card we must consider it in the parley-centric investigator that got released together with this card. Thanks to this card, Alessandra Zorzi can sort-of-evade each round as a free action, but I feel like the drawbacks of having to play this in advance (contrary to the various evade events she has at her disposal), testing a lower stat and not working against Elites outweight the saved actions (even considering the engage actions you would normally take to evade an enemy engaged with a friend) and deckspace. I can see it in a level-0 deck if you have few other options, but I would upgrade out of it fairly quicky.

When it comes to the "special effects" of this card, they leave me pretty confused. Testing against health is rarely an advantage, since the few times the evade value is higher it usually means that it's easier to just kill the enemy. Giving them aloof instead of exhausting them honestly just sounds like a disadvantage: can't attack them without engaging, they will move during the enemy phase if they're hunters and you can't engage and move them around freely if you need it for some enemy-to-clue shenanigans.

All in all, looks like blackmailing ain't worth it.

The effect, making an enemy aloof for a round is quite nice -- it is frequently better than conventional evasion. A frequent awkward experience when investigators split up is that a seeker will spawn a hunter enemy while they're separated from the guardian. If the seeker evades, clears the location, and moves out, then there's no inherent reason for anyone to go back in. But if the enemy is left alone they will hunt and attack someone the following turn.

If you make a hunter enemy aloof you can move away and let it move onto and engage your guardian without getting to attack him.

Sadly, I don't see many characters with rogue access wanting to play a 2-cost asset that allows them to spend actions to make will tests vs only non-elite enemies against sometimes quite high skill requirements. So this seems pretty bad. But it probably will show up here and there as scenario tech because you can tuck it into underworld market, boost and discount it with Sleuth, and so on.