Keep in mind that in order to construct such a spell the wizard involved would need either an extremely high lore, or spend lots of time making aspects and sitting out scenes to make the difference. That's how it's meant to be. If you take the time to manufacture the spell you can do whatever you want. But your lore hinders you, your conviction slows you, and you discipline is the only thing between you and a messy end.

The thing to remember is that in Dresden the reason that vamps and such can't cross thresholds isn't that they are physically incapable it's that without an invite they leave behind a huge chunk of their power, and most of their power is already tied up in keeping them ambulatory/corporeal/on this plain of existence and they wouldn't be able to function once they did. 

I recall in grave peril, while Harry does require an invite from an actual resident (Murphy doesn't count) he does state that the fact that cops and emts have been going in and out so much that the threshold is torn to heck at the moment. I would say that while a mortal can pass through a threshold without bothering them, it does hurt the threshold. A church has a strong threshold because it isn't a business to the people who go there, it is a sort of second home.

I agree with questioning why it would help with social defense, it might give you that extra second to think of a good come back but I don't think it would help someone that wasn't already good at bantering. And really I don't think seeing something would help with dodging it that much either (it would help but not to the point where your actual skill at dodging wouldn't matter). It would improve your ability to react but react too soon and they'd just adjust their aim to where you moved to. I'd change it to a flat +2 to physical or a +1 to both depending on the GMs preference. Possibly with the restriction that you need a higher lore than the relevant stat to get the bonus at all.

  The alternative might be making a crafter that stores luck-based effects in enchanted items or potions.  Standard Evocation with no mods won't work under the RAW, though.

I actually did this for a short lived game awhile back. It was basically an enchanted item that stored a set number of shifts, I think one less than the character's lore or maybe half, it's been awhile, that could be used to alter a result on a die one step. Worked fairly well as I recall.

Hello so for my first story arch in a game I'm planning on having the group deal with a pack of Lycanthropes causing problems in Boston. The Leader and his lieutenants are going to be smarter than most so it's not going to be a pure combat plot. The PCs are at chest deep and here are the basics of them:

A champion of God ex supernatural killer for the yakuza
A Kinetomancer Apprentice Ex-con artist
A troll Changeling
An emissary of the Archive, essentially a hereditary kincad that reawakened a rejected family power and responsibility.
A Master Mechanic Mortal
A black sheep White Court Vampire of house skavis that breaks up human trafficking rings and eats the victims despair to try and help them heal.

I'm thinking the Lycanthrope Gang is Run by a one armed gent who calls himself Garm. He's brighter and more methodical than most of his ilk and will be stated as submerged.

I'm thinking 3 Chest deep Lieutenants running varies operations, Protection, Chop chop, Smuggling, etc.

Maybe a dozen generic punching bags and one or two feet in the waters with potential.

Does this sound decent? This isn't something I want wrapped up in one or two sessions and even after the main trouble is solved if they prove effective foils I'll keep them around. The party will probably never meet all of these guys at once either. Just need some input. Maybe some good  ideas for the LTs.

Well Dresden files has two types of "demon's" You have your fallen like the Nickelheads and your standard Nevernever nasty like Chauncey. Supernatural demons are rather different from either; they are corrupted human souls that take over those that are susceptible. I suppose presenting them as a form of shade would work to a degree, though in that case the "educated" would probably find people calling them demons to be very wide of the mark.