So I think there's 3 important things to note about this card that you might have skipped over if you only gave it a cursory glance.

First - the will-check replacement is a reaction triggered ability, meaning you can use your will for ANY check. This makes it markedly different from your normal fist check Shrivelling or Wither which can only be used on a fight action but cannot be used to open a locked door, your normal book check Rite of Seeking or Sixth Sense which can only be used on an investigate action but cannot be used on book check parlays or when you are using an investigate action that is printed on a location or the act/agenda, and your Mists of R'lyeh which can be used to evade but not to beat the evasion check on encounter cards.

Second - this asset takes up BOTH arcane slots, so unless you're using Sign Magick, you won't be able to have this card and one of the more specialized cards mentioned above out at the same time.

Third - the card is Myriad, meaning when you get it, you're allowed to put 2 more copies of it in your deck for free (so potentially 2xp total for 3 of these guys).

So is this card good? Eh... probably not. The 2 arcane slot usage makes it very difficult to put in a deck. Ultimately once you're in the lategame, Mystics are going to be relying on the powerful effects that their upgraded arcane slots bring. From Shrivelling you get 3 damage attacks with a +3 will on your roll, and with Sixth Sense and Rite of Seeking you're looking to get multiple clues with one action with a +2 will on the roll. Simply swapping out your fight or investigate action with will without any bonus to the roll really hurts (though granted you'll probably have a Holy Rosary and possibly Four of Cups to mitigate against the need for the bonus) - and not having any bonus damage or clue pickup per search makes the card lackluster.

Now of course, the benefit I discussed first, that it can be used in any type of check is immensely powerful. But Mystics already have good tools for dealing with these sorts of checks. If the check is coming from the encounter deck, you can just cancel it with a Ward of Protection (or the level 5 version Ward of Protection if you're playing solo). Otherwise you can fix the token bag for non-investigate or fight action skill checks with cards like Dark Prophecy or Defiance or Counterspell or even Seal of the Elder Sign if you're feeling spicy - and this is not to mention that often a bad roll can be undone with Time Warp or the effect ignored with Deny Existence. So you're paying a very hefty price (the loss of the bonus will to the roll, as well as the extra damage or clue benefit discussed above) to cover a weakness that Mystics already cover very well anyway.

The other issue with it is its limited usage. It's got 3 uses. It tries to make up for this by being a myriad (meaning once you've got 1 on field, you can still have 2 in your deck or hand), and allows you to discard them from your hand as a free action to put another 2 tokens on. If you go with that option, that's 7 uses. That's it. 7 uses total, and it cost you 3 cards! And the entire time it is up, it is hogging both your arcane slots, so you're using it for every check - you can't leave the fight and investigate checks to the specialized arcane spells because you can't have those out! So these burn off pretty quickly. Of course, you could replay them instead - but in that case, you're paying 6 resources and 2 actions for just 2 tokens - so that's almost never going to be worth it.

That said, I can see some use if you are planning on running Sign Magick x2. If you can keep this card in reserve so you only have to use it on the checks that your more specialized cards can't do, it can probably be used as an alternative to all the cancels I discussed above. But the setup is harsh - 9 resources to get both Sign Magick and this card out, and your hand slots are gone (so no The Chthonian Stone or Ritual Candles if you were planing those, and no Twilight Blade - not that Diana Stanley would ever want to get rid of the cancels anyway).

The other potential benefit of this card is that it can act as a buffer card if you're having trouble finding your spells. We've all had our Shrivelling and Sixth Sense at the bottom of the deck, and having a myriad card like this with 3 copies to give us the willcheck substitute we need in a pinch has undeniable value. The issue though again is that it hogs both arcane slots, so once you find one of your specialized cards, you're going to have to discard this card to make room for the specialized card if you want it out on the field. This a problem because that means it will fail to substitute for the second card (for example, if you find your Shrivelling first, then you'll have no way to cover investigate checks until you get your Rite of Seeking.) So it is really only an effective substitute so long as you have NEITHER of the specialized cards. So you're better off just using the tried and true Arcane Initiate initiate x2 to find your spells rather than rely on this as a stopgap. And to add insult to injury, this card only has a test icon of +1 will, so it's not even that good when committed to a test - so if you're using it as a substitute card and you draw it late, it's almost a dead draw.

Use for any check. A rather brilliant effect that occupies the entirety of the class's most important asset slot.

First off, rules wise, keep in mind that you may not keep existing bonuses that might be in place for the tests you're replacing, if you use Mind's Eye to change an attack with an Knife for example, into a test you loose the +fight from the Knife because it's specifically a +.

Furthermore, since the test is changed when it's initiated, you cannnot commit cards of the original type to the test, thus you cannot commit a Deduction or Vicious Blow to Mind's Eye tests.

Mind's Eye unlocks a new role for characters to play. Usually a plays the "Flex", someone who can kill enemies and get clues, but often only after opening a certain window of power (I.E, buffing and playing the appropriate spell assets).

The new role is "Manager", the character who greases up gameplay for the team by digging out teammates, getting key evades, clues or just sniping a hard skill test required by a scenario card. Using Mind's Eye and some classic buffs a can punch an Acolyte and turn right around to pull up a clue from a 4+ shroud location and then parlay a tricky scenario card, all in the same turn and make it look easy!

One issue to Mind's Eye is that it's a way to beat tests, but it does'nt speed you up any, there is no damage bonus, no extra clues. You can however use it to swap around stats on some very weird tests, an investigation attempt with a Flashlight, executing an "I've got a plan!" or Waylay, obviously you can also play some tricks with guns and tools that grab clues or deal damage.

That said, it can still be slow going to use Mind's Eye for everything and charges are limited, so lean into that Manager role and use it not to get everything done yourself, use it to make sure everybody else is operating at top efficiency.

You can build some interesting and fresh variations of characters with this card, it really shines bright in off-class characters, especially Patrice Hathaway.

I think an overlooked use case for this card is in Daisy Walker. Her willpower isn't that great, and it isn't often worth using spells that don't boost , and the ones that do boost it are too high level for her. She's not too likely to use arcane slots aside from Arcane Enlightenment or some other niche cards.

Obviously she's never going to substitute , and she doesn't need to. And it seems at first that getting a boost of only 1 to (without extra damage) or isn't really worth 2 xp, 1-3 cards and both arcane slots, but the most important consideration is Higher Education. Since it's a permanent, this combination of cards can convert any test to something that can be astronomically boosted with only a little bit of money, something that's easy enough to come by as seeker, and cards in hand, which are also easy enough to come by in that class.

It's not something that lets you fight primarily, but it can finish off a weakened enemy, and it can let you evade when desperate. It's also good at dealing with the rarer or even treacheries.

Also worth a consideration are all the seeker cards that interact with secrets. Eldritch Sophist and Truth from Fiction let you keep it around even longer, and the former lets you move charges from it to stuff that's more useful as the situation calls for. With that in mind, the three copies can be extra easy and fast secret gain, for use with other great secret assets, of which a few have been teased for the Innsmouth cycle. Though some of them also compete for arcane slots, Daisy can run Familiar Spirit in a pinch, or just run the very best slotless or Tome assets that use secrets. Old Book of Lore is a particular standout.

Overall, it isn't really necessary, or something that seekers don't have tools for already. However, most of these tools are events, and having something permanent - secret supply notwithstanding - on standby for turns where Mind Over Matter would feel like a waste is pretty good.

I feel this card is most useful for Sefina Rousseau. Sefina has a Willpower of 4 and is naturally event-focused. She's likely to see this early as well thanks to 3 copies from Myriad and a 13 card opening hand. Lockpicks was already fairly strong for her, allowing her to investigate at a base of 6. Lockpicks + Mind's Eye allows her to investigate at a base of 8 (or 9 with Holy Rosary), making it much more likely you can hold onto those Lockpicks supplies at high-shroud location.

While it does compete with Double, Double and Suggestion for your Arcane slots, it's significantly cheaper in exp than the former, and gaining 3 copies on purchase makes it a more consistent find than the latter. Consider taking Mind's Eye as an early purchase while saving towards the 8 XP for Double, Double, then afterwards grabbing a Versatile to throw in your favorite off-class event, a Sign Magick or two, and more of those fantastic rogue events (alternately, some Guts or Lockpicks if you want to mitigate some of the consistency penalty that comes with Versatile's extra cards)

Will this work with Gloria? IF find once she has teamed up with Alyssa she sails through the scenario until made to take a strength/foot test. Then she is stuck. It does limit her control for enemies she has to fight to Spectral Razor, Ethereal Form, or sword can without sign magik to hold her spells. But that is often enough.