The basic or specialist-ized versions seem like they reliably give 3 or more wild icons almost all the time if you do a little planning and jumping through hoops. But Survivors have always been able to get lots of wild icons on 1-2 XP skills and occasionally on 0s. This one is solid but not especially exciting as far as that goes.
Mythos-hardened seems pretty bad outside of extremely niche counterplay situations. I rarely want to spend that much XP just to prevent one copy of one treachery from coming back, let alone limiting myself to a subset of traits and requiring a test and locking up an otherwise good card. "Fool me once..." and The Eye of Truth put this to shame.
Nemesis seems okay as multiplayer support (take elite trait for boss fights) or to enable Exploit Weakness, but I have little to say about it. No, the only really interesting part of the card, IMO, is Always Prepared, which lets you return one of these cards to your hand once per round if you draw the right kind of encounter. In one sense, 5 XP feels like a lot to spend on a card with no action compression at all, just to pass tests. On the other, a lot of decks do run multiple 2-3 XP assets that are mainly for skill boosting and test-passing. If we can actually make this trigger at least every other round, it might be worth while.
One nice thing about Always Prepared is that while Nemesis and Mythos-hardened only trigger if you actually commit Grizzled against the encounter card, Always prepared doesn't require you to be testing against the card at all. You get it back in your hand to do whatever you like with as long as you drew the right type of card. I believe it should even work when you draw weaknesses from your own deck, if the traits match.
This will be especially valuable if you have special incentives to commit cards to tests (Sea Change Harpoon), other uses for cards in hand (Wendy Adams, Cornered, Celaeno Fragments), or a tendency to draw extra encounter cards (Kicking the Hornet's Nest, Drawn to the Flame, Nature of the Beast, Nine of Rods).
I can especially see Patrice Hathaway taking this traited with "monster" and some common treachery traits like terror, hazard, or madness. She'll get one in the discard early and pull it back every time she hits a monster in the encounter deck, draws into her personal weakness, or fishes out a treachery, and she can just throw it into an invetigate or away for vioin money. If she misses she can fish with Drawn to the Flame and Nature of the Beast for more matches. "Ashcan" Pete can do most of the same stuff.
William Yorick can go tell others to "Let me handle this!" or take First Watch to make sure he gets his triggers in. (Calvin Wright also gets some of these options).
It's never going to be as viscerally exciting as firing up a Lightning Gun, Seal of the Elders, or The Black Fan, but I think it has enough value to be worth a shot.