Thanks for all the responses. Here's a bit more info...but as a few of my players may glance over at this board (Ryan, Mike, and Gary, I'm talking to you!), I'm hiding the spoilers.
(Is there any way to do spoiler blocks on this board?)
There are 5 PCs, all Submerged, with the following high concepts:
* Wizard M.D. (1 Refresh, 9 spent)
* Bouncer (1 Refresh, 9 spent)
* Reluctant Avatar of Kali (2 Refresh, 8 spent)
* Bearer of the Staff of Enoch (2 Refresh, 8 spent)
* White Court Vampire Searching For Something More (1 Refresh, 9 spent)
The 'big bad' is actually being set up for a fall by an even bigger bad guy. The area's White Council Warden was tipped off by the "bigger bad", and attacked an assembly of the Red Court with nearly every wizard in Colorado, causing massive devastation to both sides. The Red Court noble went to ground, and has his second-in-command running his operations while he consideres his options. Unfortunately for him, the bigger bad has manipulated the second into making some really horrible choices, which has caused the rest of the Red Court to cut their losses and leave the noble hanging. Likewise, the PCs don't have any support from the White Council, as the only surviving member in Colorado is one of the PCs, and the Council doesn't have the resources to send backup. The goal of the bigger bad is to play the groups off against each other, leaving both sides so weakened that its plans will continue unopposed. It would prefer that the PCs survive (for now), as they are useful tools...but it won't be heartbroken if they die.
So, the villain has some brand-new Red Court vamps created from homeless people and gang members taken off the streets. He thinks the Warden died in the fighting, but isn't sure. He doesn't know the PCs are closing in on him...but he's playing it safe.
As to the identity of the big bad...well, he's located in Richthofen Castle in Denver, and the PCs are pretty close to figuring out his identity. Rumors of his death were greatly exaggerated...he survived the near-fatal injuries long enough to be turned, and another body was substituted for his. Here's the stat blocks for him, and the new spawn of the Red Court:
Baron Albrecht (Manfred von Richthofen)
Aspects: Red Court Baron, WWI Fighter Pilot, Ace of Aces, "Le Diablo Rouge" (the Red Devil), Cold As Ice
Traits: Distant, Unemotional, Humorless
Firearms +6, Driving (Piloting) +5, Weapon +5, Alertness +4, Athletics +4, Fists +4, Discipline +3, Endurance +3, Presence +3, Conviction +2, Deceit +2, Intimidate +2, other skills at +1
Addictive Saliva [-1], Blood Drinker [-1], Claws [-1], Echoes of the Beast [-1], Flesh Mask [-1]
Feeding Dependency [+1] affecting the following powers:
* Cloak of Shadows [-1]
* Inhuman Strength [-2]
* Supernatural Speed [-4] - Always go first, +2 Athletics, move two zones as part of physical action without penalty.
* Inhuman Recovery [-2] - Remove mild physical consequence 1/scene as supplemental action.
* Supernatural Toughness [-4] (Catch is sunlight, holy stuff, no armor on belly)
Item of Power [-5] - Grants Physical Immunity (magic), secretly provided by the bigger bad, replacing an identical item that the Baron normally wears. The item will 'burn out' after the Baron dies, or on the following sunrise.
Tower of Arrogance (as Tower of Faith): Social/mental armor of 1 until his enemies have the advantage
Riposte: After successful defense, sacrifice next action to immediately hit. Do not gain shifts for Total Defense when this is used.
Physical OOOO(OOOO), Armor: 2
Social OOOO, Armor: 1
Mental OOO
Weapon: 4 (rapier or claws) or Weapon:2 (.45 ACP Luger)
Dodge: +6 (Athetics +4 plus Supernatural Speed +2)
The item of power is a bit of a stretch, but is well within the abilities of the bigger bad to provide.
Red Court Vampires (newly created)
Fists +3, Stealth +3, Alertness +2, Athletics +2, Deceit +2, Discipline +2, Endurance +2, Intimidate +2
Addictive Saliva [-1], Blood Drinker [-1], Claws [-1], Echoes of the Beast [-1], Flesh Mask [-1]
Feeding Dependency [+1] affecting the following powers:
* Cloak of Shadows [-1]
* Inhuman Strength [-2]
* Inhuman Speed [-2]
* Inhuman Recovery [-2]
* Inhuman Toughness [-2] - Catch is sunlight, holy stuff, no armor on belly
Physical OOO(OO), Armor: 1
Social OO
Mental OO
Weapon:4 (claws)
But beyond game mechanics, you have here a senior RCV. You want to play him/her smart. He/she (hereafter; he for short) doesn't just set traps and make sure he's got an escape route (though he should have both), he seduces, addicts, or buys a host of human shields. You know, the sort of folks the council would take a VERY dim view of being killed by magic. He should be making alliances with other supernatural forces so that if the PC's kill him, they will make an enemy of someone even worse - and he should be advertising that alliance, for deterrent effect. He should be setting up "dead men's switches" on the PC's families so that if he doesn't radio so-and-so by 1600 today, they die. In short, if he is a major Big Bad, he should be doing everything in his power to make the PC's not want to kill him, because its not worth the cost.
...
Now, since you say there is another big bad setting this guy up, you might use only one or two of these effects.
I'd actually classify him as a minor Big Bad, while the real Big Bad is setting things up so the PCs will suffer the fallout for killing him. The Baron is smart...but uninformed. He's in his ivory tower, without a clue as to what has been happening on the streets because his trusted lieutenant is his only source of info...and that lieutenant has been misled and manipulated into keeping information from the Baron.
So, what does the Baron have? He has a private security force guarding during the daytime, while thralls and newly-created RCVs are close by at all times. He will advertise that killing him will bring down the wrath of his uncle, the newest Lord of Outer Night...but the PCs already know this, so it won't have any further shock value.
The Baron's problem is that he doesn't know about his own weaknesses. He doesn't realize that his alliances were shattered, as that happened after he went to ground. Even worse, he doesn't know the PCs are after him. He expects a reprisal from the White Council, which means he's set up what defenses he can versus wizards. He doesn't realize that there's a White Court vampire gunning for him, nor does he know about the newly-created warrior of God wielding a weapon that is his bane.
Sure, you can ratchet up the tension of the final confrontation by throwing more raw force into it. But you can also ratchet it up by making it relatively easy to kill him, but making the choice of whether to do so really intense.
In this case, I want the PCs to kill him...or rather, the Really Big Bad behind the scenes wants that to happen, and is setting everything up for this to occur. The White Court Vampire PC with "Better Dead Than Red" is here partly because the Big Bad brought him to town, knowing that he would become involved. So it's less about the tension than whether the PCs can figure out that they're being played. Even if they figure it out, are they going to be able to overcome their own motivations for killing the Baron?
The key here is what type of game are your players expecting. If they expect to crawl through the RCV's "dungeon" and unload a ton of Fate Points on round 1 and go home, how would they react if you rain on their expectations?
I think they'll be fine with it - they will realize that a quick, easy kill of the Big Bad may be an ego boost, but it won't make for a fun campaign.
Depending on the type of game you are GMing (and it appears quite high powered), perhaps you should ask yourself if the RCV should not be outclassed, even though he is your big bad with every ploy that he might try to stop the PCs either being stymied or countered.
It's about as high-powered as you would expect from a beginning Submerged game. It's not anything like the games where people are starting at 15+ refresh, but each PC is as tough as "Storm Front" Harry. Whenever Harry is teaming up with people like Thomas, Michael, and Murphy, he can face off with some seriously major-league threats...and I expect to carry on that tradition in my game.
I expect the Big Bad to be defeated...but it will be a close thing, and the battle will be decided by player ingenuity and a few outside influences hedging their bets. Despite everything working against him, the guy is a Red Court noble with a lot of RCV's backing him up.
In short, if the PCs know the BBEG is holed up somewhere, that the BBEG and most of its minions are not human and they got at least one spellcaster in their group, the monsters are dead. With a few PCs to provide consequences and fate, a powerful ritual is a matter of minutes, not hours or days. And since monsters can neither create nor pass magic circles, they cannot take advantage of that kind of defense. Not that a magic circle or even magic immunity is gonna do squat against a meteor crashing at 20 miles/second on your head anyway.
If it was that easy, why didn't Harry do it? I think you're looking at game mechanics, rather than the flavor of the series. The only person to ever call down a meteor on a place was the Blackstaff. He not only had the power to do it, but also the expertise to place it exactly where he wanted it, and a way to cheat the 1st Law. A starting PC wizard should have none of those things.
I think people are carrying the Thaumaturgy rules too far. It's a weakness in the system - if you have trouble dealing with Rules Lawyers. If anyone could call up unlimited power when using Thaumaturgy, there is no distinction between a hack spellslinger like Victor Sells and members of the Senior Council. Victor could throw some pretty major-league stuff...but he couldn't take down Harry despite having a direct thaumaturgical link to him, and the consequences from doing so got him killed. Any GM who just lets the PCs whip up a ritual in minutes to take down the BBEG shouldn't be running Dresden Files. If the PC Wizard in my group tried it, I'd be hitting the group left and right with compels (like Too Much To Do causing interruptions)...
...not to mention having the even bigger bad intervene, since a nuke from orbit won't further its goals.
I mean come on if you make the guy the Red Baron, you at least have plan it where his minions slow the party down long enough so he can get into his plane and have at least one flyby exchange, even if the players knock him out of the sky he should still be a threat as with his toughness he should survive it (if any red court could actually fly/glide he could).
You would just be wasting a perfect opportunity otherwise. Come on can you just imagine the player’s faces when they hear the roar of an engine, after finding a couple medals and pictures in his house if they didn’t know who he was before….
Nevermind the fact that a machine gun (weapon 4) that could hit multiple zones is seriously dangerous when he starts tagging aspects and that’s discounting anything else he could have on it (there are so many wonderful things you could put in a crop duster, unless want to go with simple napalm bombs or nerve gas).
*Shrug* would also be great to let him get away and come back to help the pc’s later against the actually big bad… As he would have known someone sold him out. Most intelligent wouldn't go after the pawns (the pcs) as much as the guy behind the attacks.