((If you want Fiona to get an AC to home,myoull have to do something along the limes of what Tranquillina did. It's not exactly a pristine source...))
Duncan disappears and the spell hits Talia turning her into a pig. His disembodied voice sounds, "You didn't think it would be that easy, Fiona. Did you?". Talia as a pig charges Fiona and oinks at her quite raucously. Outside the sound of what can best be described as an avalanche is heard.
((Yeah, I was thinking of using his fluid to bolster the penetration, but if it had been a while, his wouldn't have been the most recent. And can you miss with a non-targeting spell? I thought it was either it works or it doesn't.))
Fiona looks down at PigTalia, and realizes that her Perdo Vim isn't nearly good enough to dispel her spell...although she might be able to pull of The Beast Remade if she can get past her Animal resistance.
[color=blue]"How powerful is your resistance to Animal?" she asks.
Wait...."DUNCAN cackles"?!? (or was that a typo?)
Can you miss with a Pilum of Fire? They are bot technically not "aimed" spells. If you can with Pilum, then so should it be with other spells. And I only said Duncan like 30 times...
((I don't think you can, since there's no aiming mechanism involved...unless it's "if the target isn't there anymore when the spell goes off, it hits what's closest to where he was" type deal. I could be wrong, though.))
Yeah, and I apparently missed it 29 times, my eyes turning Duncan into Douglas. Apparently his shape-shifting spell had...unintended consequences. 
I could be, too, but his leaping away could be considered to do exactly what you describe, in which case it didn't hit Talia, and Fiona can instead have a ticked off maga in front of her going off on her in Itallian.
((Or Duncan, suspecting that he would be dealing with Fiona at some point, has some kind of MuCo-shunting ward up, knowing that Curse of Circe is her go-to "combat" spell. Not going to worry that much about it, although Fiona would like to know how he did that so she can find a way to keep it from happening again.))
((She can probably fix it with a The Beast Remade, but she very much doubts that the maga would trust her enough to lower her Parma for it, so, assuming she doesn't answer...))
[color=blue]"We'll find a way to fix this in a couple of minutes. Are you going to stay here, or come outside to see what's going on with the tree?" Either way, Fiona's headed outside.
Outside the Black Fir appears to have been uprooted from its spot near the tent and is now near the Tower of Bonisagus. The vines surrounding the tower appeared to disengage from the tower and have now surrounded the tree and the two seem to be locked in an odd wrestling match flora-a-flora. Several magi have arranged themselves nearby and appear to be ready to cast spells, but unwilling to do so based on what is happening.
Talia squeals like a pig...
Fiona takes in the scene, her jaw dropping. [color=blue]"Bloody hell!" she says in Gaelic, then turns to one of the nearby magi. [color=blue]"What's happening?" she asks, totally not caring that she is stark naked, possibly except for the mask.
[color=blue]"I can probably fix that right now," she says as she crouches next to her, [color=blue]"but I'd need you to drop your parma for a moment. If you agree, tap your right paw. If not, your left."
(( Everyone in favor of renaming this thread "I Don't Know Who I Did That Summer", raise their right paw... 
))
((PB may not have thought of this, but i think Fiona might have an epiphany: dont ever go away for Tribunal again. After this, Fiona will move heaven and Earth to get the Normandy Tribunal meeting at Mons Electi. Tribunals away from Mons Electi have some bad mojo for Fiona...))
Talia oinks loudly and seems to nod her head in agreement to Fiona.
Several of the assembled magi, all in various stages of undress and most still masked are still discombobulated when several other magi rush onto the scene, or out from the Tower of Bonisagus. The vine seems to be holding the Black Fir back from the Tower, but it doesn't seem to be able to do much else...
Fiona casts The Beast Remade normally (firm voice, bold gestures) on Talia. (Her CT is +35, spell level is 25. Does she need to roll, or will penetration be relevant?) If the spell works as planned, Talia returns to normal, except that her hair will be snowy white until the spells end.
Fiona is stark naked except for her mask, but doesn't really care at the moment. She will find someone who looks like they might be in charge (or at least a lieutenant) and walk up them. [color=blue]"What's going on? And what can I do to help?"
No one looks like they're in charge, it's bedlam, at best.
Towards the border of the covenant's grounds, it seems as if an Army is forming from the forest itself, waiting for something to happen. Fiona, through all the distraction manages to return Talia to her true form.
Talia cries out, "Grab anything you can we can set afire, and we'll burn that tree to the ground!"
Someone cries out, "But it's a vis source of Durenmar's"
Talia retorts, "But the library is a bigger one, you dolt!"
Some people begin doing what she said, and they either light them afire themselves, or she does it on their behalf. A group of them approach the tree, and it's branches swat them away, and what fires do get started on the tree, it quickly smothers out.
"I'm out of ideas, and I doubt I can manage to damage the tree with a Pilum of Fire, myself. Someone get a Flambeau worthy of the name to help ignite this tree!"
((Just to clarify, since with magic you can never be sure, but when you say an army is forming from the forest itself, do you mean literally, like an army of treants? Or figuratively, like an army is coming out of the woods?))
It looks to be an army of multiple humanoid figures...
(( I pull in resolution, and begin
To doubt the equivocation of the fiend
That lies like truth: 'Fear not, till Birnam wood
Do come to Dunsinane:' and now a wood
Comes toward Dunsinane. Arm, arm, and out! ))
((Maybe I'm missing something here...in fact, I probably am...but I'm not seeing what help Fiona can be here. She doesn't have really much magic that would be offensively capable against it. She can try to spont a version of Probe Nature's Hidden Lore on it, for whatever size mod it has, and try to get some intel on it. Other than that...I'm stumped.))
((Oh, and the army of humanoid figures... can Fiona tell if they're friend or foe? Int 1 + Folk Ken 1 + die roll of 5 = 7.))
((So, I just read the wedding scene in A Storm of Swords a couple of days ago. And I'm having the same feels with this bit of the thread that I felt when I read that. No spoilers, though, but if you've read it, you know what I mean.))
Fiona's mind races, coming up with ideas but discarding them just as quickly. It all boils down, as far as what she personally can do to the tree, to the fact that the thing is just too frelling big for her to affect. After a brief moments of standing there stunned, she starts to look around, trying to find anyone who looks even vaguely Flambeau-ish, or Tytalian, or looks like they know more than she does about Ignem (or possibly hella-powerful with Herbam) and tries to sic them on the tree.
Even as she works, she keeps looking that way in horror.
(( If you mean Rob Stark's wedding, yeah, I'm getting much the same vibe. ))
((Yeah, I just realized this morning that there are more than one wedding, but I did mean the one at Walder Frey's. Edmure Tully's to Roslin Frey (Rob married Jeyne off-stage).))