OK, so it's a hectic morning here and I haven't actually gotten to browse through the spoilers until now…
That said, HOLY COW! There are some really cool cards (again) in this pack and I must have it!
With four new Necronomicons in there I expect they do want to make this Gencon legal as it's a cool theme for the game - the Necronomicon is just so iconic.
Padma is cool. Pricy, but cool. Urumi looks good too, making a character into a wrecking machine at stories. Put it on someone hard to kill and they'll really be annoying. Necronomicon: Owlswick is a board clearer, and a darn fine one.
Kaleidoscope is nice, but doesn't get around Willpower/Terror. Still, it converts a smaller effect into a bigger one. Named by the Unnameable I like better, it really supports a Lunatic based deck nicely.
Great Library looks like another card to help get Tomes more widely used, nice. Eryn clears enemy Tomes, seems pretty situational. Necronomicon: Al Azif helps a rush strategy and should fit in well with Miskatonic's playstyle. Makes me want to build a nerd deck right now
Ya-te-veo is a cheap Dark Young with a mini-shotgun, nice. Three Bells is pure coolness, Shub is already good at putting out lots of characters - now you can trade them for your opponent's better ones and maybe steal a good one later in the game.
Ritual of Exclusion looks very tasty, this is immediately going into my Silver Twilight deck. Magical Theorist makes ALL their lukewarm rituals more useable - exactly the sort of thing they need IMHO. Their Necronomicon: John Dee is probably the weakest one in the pack though which is a little sad since Magical Theorist rewards Tomes and several of their other characters do. Look for them to want to team up with the factions with good books.
Inside Man lets you filter the top of anyone's deck, a solid character. On the Run fits in with Syndicate's usual story control effects.
Tindalos Alpha makes up for the relatively lame "Hounds of Tindalos" card by giving back 2 cards when he dies. Necronomicon: Theodoras Philetas give you a bit more milling, but I think we've got enough of that for now so it's more of an option than a must-have. Pulled from the Beyond though is a great card to let you steal from your opponents discard pile to temporarily borrow their useful characters and supports. Classic Yog.
Overall, a really nice pack with solid cards for every faction.