Couldn't you also theoretically use the ring in a similar manner to Harry's Force Rings?

Ex.- I aim the ring at an overhanging rope nearby and release the energy, causing the rope to break which in turn drops a sandbag that lands on a nearby rake which subsequently flings a can of paint at my adversary?

Maybe I'm thinking of entropy in too much of the "bad luck/curse" sense but I could see some ridiculous, fun situations coming from a focus like that.

I'll put this in spoilers because it deals with side stories/comics that may not have been read by some, but here's what I remember of the Venatori Umbrorum.

(click to show/hide)

The Venatori Umbrorum are a mortal covert/para-military organisation headed by the Archive and are dedicated to fighting the Oblivion War. The Oblivion War is a long term war that aims to reduce the access supernatural entities have to the real world by eliminating information about them, thus cutting off their ability to break through the barrier between Earth and the Nevernever.

They're known for using mortal weaponry, up to and including explosives/flamethrowers. In the War Stories comic a member of the Venatori is linked by magic to a Shoggoth (Outsider) and is tasked with keeping it tranquil until the time comes when it may be needed. This plan is upset by the arrival of Harry Dresden and an army of Red Court Vampires.

To the general public (or at least those who know of them) they are simply an organisation of mortals who are allied to the White Council.

This sums it up pretty well. Although I would add that:

Do you do suggestions or critiques for character builds at all? I've got a write-up for a descendent of the Grimm Brothers who is working together as a mercenary with one of my PCs and am looking for some advice.

So I did a tentative write-up for Jack with abilities and Aspects. I probably statted him out too low if he's supposed to be closer to God-level but I feel like this pretty accurately reflects his overall skill set.

High Concept
Pumpkin King of Halloween Town
Trouble
This Halloween Must Be Better Than the Last!
Other Aspects
It’s My Job (But I’m Not Mean)
The Erlking Leads the OTHER Halloween Tradition
What’s This? What’s This? (Representing his knowledge [or lack of knowledge] of the NeverNever and his penchant for breaking into song)
 “You Know I Was Santa Once”
You Don’t Want to Know What I’m Fully Capable Of (reflecting his dark nature)

Skills:
+6   Intimidation
+5   Athletics Stealth
+4   Alertness Performance Presence
+3   Discipline Fists Lore
+2   Burglary Conviction Might Rapport
+1   Craftsmanship Endurance Investigation Survival

Stunts/Powers:
Spider Walk (-1)
Supernatural Sense (Detect What Will Scare Somebody) (-1)
   Master of the Scare (-1): Roll Lore + 2 when making assessments or declarations to know what someone or something will be scared of/by
Inhuman Strength (-2)
Supernatural Speed (-4)
Inhuman Toughness (-2)
Supernatural Recovery (-4)
   The Catch (+0) is any act fueled by Pure Courage (this is a very tentative Catch)
Demesne (-1) [Halloween Town]
Cloak of Shadows (-1)
Incite Effect [Fear] (-1)
   Incite At Range (-1)
   Incite Lasting Effect (-1)
   Incite Potent Effect (-1)
Modified Glamours (-2):  May use Discipline or Intimidation to create Aspects related to scaring somebody (these may also be used to alter Jack’s physical appearance)
Were You Scared? (-1): Gain a +2 to the Playing to an Audience trapping of the Performance skill when trying to be intimidating or scary

Total Refresh:
-24

What about your performance in the previous times you ran did you not feel satisfied with? Was it just setting up encounters and keeping the story fun or something else specific?

I'm actually in a similar situation right now where I recently started running my first real campaign after having been a long-time player. Personally I've found that getting input from your players can go a long way to help the GM out. As dragoonbuster said before knowing what your players' strengths and Aspects are can really help you with creating cool moments for everybody to relish in and get more invested in the story. For the Dresden Files system you actually have to sweat the small details less - especially as a new GM - as you can get some input from your players and let them take the narrative reins at points as you see fit to let them flesh out their own story while making it seem like you had planned for it from the very beginning.

You also may want to discuss with your players just what sort of RP'ing experience they are looking to get out of the campaign/the characters they are playing and incorporate that into your planning process. If they want to do a more stealthy/investigative campaign prepare for more intrigue and clue finding  - on the flip side if they want a beat 'em up campaign think of plenty of cool opportunities for your players to kick ass and be superheroes.

I really like the idea of a thaumaturgic tattoo artist, maybe you could also make it into a form of Self-sponsored magic that would allow you to perform thaumaturgic rituals or evothaum that would let you give friendlies temporary power boosts (supernatural senses, inhuman toughness/speed, etc) justified as being the result of magical tattoos. Quick question though: if you have thaumaturgy and evocation shouldn't you have 4 focus item slots all together? It seems that you only used 3 of them.

There's a lot to it, and some I can't say because it's still being resolved, but basically: High-tech megacorporation used as a front by thirteen warlocks to throw off Wardens/White Council spent forty years setting up a global ritual, centered in New York. They made deals with Outsiders that helped them develop more advanced technology and give them power. In NY (and the greater eastern seaboard) they worked through shells in shells in shells, though an organization called Azalea, that basically did two things: steal a bunch of metaphysical links to NY and create large pools of Outsider-based energies, all to set up their main ritual, bringing over a butt-load of Outsiders to the world. This never came to be, thankfully, as the PC's stopped them in time. They...well, they weren't very discreet towards the end of their plan, primarily because they needed to instill fear into people to further the goal. Thankfully, the local in-the-know mortals used the media to play it off as animal escapes and terrorist attacks.

This actually sounds like the general idea of what I wanted to do (albeit with more planning and a finished overall plot) so thanks for summarizing it up, it really helped. I think this will help me to steer my overall idea. I was talking it over with my co-GM and we came up with the idea that the fog ritual would be masked by the accumulation over several months/years of smog and pollution around the city and pollution of the rivers as a result of White Court influence in the EPA and local natural gas corporations (this would also tie in to one of the PC's background as a pseudo-Wyldfae who is the son of an eco-friendly CEO in the area).

But frankly--your plan doesn't have to be what happens. Ultimately, the goal here is to collaboratively build a story. If it screws up your plans but the story's great, then go for it! And then invent something else.

Based on my own RP'ing experiences, I can attest to how sideways GM plans can go haha. For right now I'm just trying to get an idea for what the end game will be so that I can lay down some groundwork in case I need to come up with some alternatives. That way I can come up with some fun encounters and story hooks throughout the bulk of the campaign for the PC's to experience.

If you're looking for suggestions...since you have an endgame in mind, it's probably worth laying the groundwork for it throughout the game. Ritual preparations can be going on in the background while other stuff is happening.

Thanks for your input as well Sanctaphrax! I'm going to take your idea of the ritual preparations going on in the background while they deal with some red herrings and B-plots going on in the city at the forefront. I feel like this would be the best way to achieve the end-goal that I had in mind as I can be dropping clues throughout the campaign and have the PC's mess with the bad guys' plans without even realizing what they are doing. My thought is that doing it this way makes it so that when the final confrontation goes down I can plan for the PC's either succeeding at preventing the ritual and what happens after or the ritual succeeding and what the PC's have to do in the aftermath in order to save the city.

Once again thanks for all of the feedback from everyone thus far!