Geoffrey looks to Hyre.
"The rails are supplied with spellcraft energy from the 'heart chamber', if I recall. It's the same thing that supplies the city with its water and lights. There must be survivors left in the Hearth who know how to shut it down and cut the feed to the rails." he says.

Upon hearing that, Kallista feels something building up in her core. Her heart begins to race and every beat sends a surge of nearly uncontrollable energy through her body as the titan that contacted her in the bathing house those weeks ago now calls upon her to repay her debt and defend it. An all-consuming pain, greater than she's ever known before, runs through her as her clothes blacken as if charred by some unseen fire, then shift and harden, becoming some kind of biological scale mail. Her eyes glow white hot... and above them, two more pairs of eyes appear, on her forehead and the last two anchored on her horns. She grows a second pair of wings as she gains over a foot in height, her fingers now ending in talons, her tail slams onto the platform, now heavy and long enough to drag on the ground, ending in a mace-like cluster of barbs.

When it's over, she looks like a true demon, but her mind is still her own... just barely.

Kina backs up against the railing, eyes wide in shock. Barna follows suit. Geoffrey however, stands his ground.
"Are you still in there, Kallista?" he asks, cautiously.

Aelar turns to Kallista, fighting the urge to step away.  He does put himself between Raia and Kallista, though, ready to defend his dragon if whatever was inside of Kallista moved to attack her.

INT: 14

"Sister, are you there.  Can you hear me?  What can we do to help?" He asks her, fighting hard to keep his voice calm and even...and mostly succeeding, betrayed only by a quiver at the first question and the last word.

(Well, I'll use this chance to tell you. I'm going to be out from this Sunday to Thursday. I won't be able to log in and, if I am able to, I certainly won't have the time to start replying to threads. If you wish to continue and bot Hyre for a while during that time, that's fine by me. If not, I'll be back on Thursday night or Friday morning (my time, but it doesn't matter much).)

Hyre steps back in surprise and fear. If Barna was near him, he stands next to her. Considering the place he was standing in before, though, it is most likely that Kallista is between him and Barna. In that case, he just goes backwards. Either way, he's not even trying to hide his alarm.
Even though he didn't know her for very long, he believed he knew Kallista well enough and was sure he could trust her. The things that often disturbed her - the features of her body most of the time - didn't really bother him. Purple skin? Cool, easier time sneaking at night. Wings? Does he even need to explain why he'd love to have ones? Horns? Well... he couldn't think of particular use for those, but they were no problem either. He could probably headbutt Lazlo or something like that. Tail? Great for balancing... though he'd have to be careful not to sit on it. Neither of these features bothered him in the least. Well, he also grew with Lazlo, who was half a goat. Still, he never realised why she thinks everyone would hate her because of how she looks.
This new form, though, was terrifying. Hyre didn't know Kallista can do that... could do that? Was it still Kallista? This was-Kallista-maybe-still-Kallista seemed dangerous. He could probably rationalise a way for each of her new features to be cool if one had them - well, all but the eye-glow - but it was not on his mind at the moment. Instead, his mind begins to quickly analyse the situation. What can he do if this isn't Kallista? What can they do if this is still Kallista? These two thoughts ran alongside each other, each running multiple scenarios in his head. The situation if this is not Kallista was bleak. If thing attacks them, the only one who would stand a chance is Geoffrey, maybe. If this is Kallista, though...

As he does what he does best, the process calms Hyre a bit, though he's still scared. He keeps looking, waiting to see was-Kallista-maybe-still-Kallista's actions. What else could he do? Aelar was brave, he was not. His mouth felt dry and he probably couldn't speak even if he tried. Of the three typical reactions, freeze was his favourite one, after all.

"Ya..." Some small part of her twinged when she saw everyone back away, but Kallista crams it down in her stomach for the time being. She turns to look out towards the city. "They're under the city," she says. "We need to shut down the Heart Chamber."

Hearing her voice, Aelar knows she's fine, her appearance not withstanding.  He steps forward and grabs her in a hug.  He whispers to her, "You'll always be my sister, no matter what!"  After holding her a moment longer, he steps back, saying, "Cool.  Let's do that.  Do you have any ideas?"

Hyre relaxes hearing Kallista's response. He could ask about the transformation later, but for now, he knew he should probably not. After a moment, he finds himself able to speak again. "So... ah... save Grimbuld first or shut down the Heart Chamber first?"

Kallista flinches away from Aeler. "D...do we know where he is? If the people in the Hearth can shut it down then we need to get there first."

((The vision Aelar had gave him the impression that Grimbuld is either in or very near his shop.))

Geoffrey looks surprisingly calm about the whole matter, as if he's seen or heard of something like this before.
"So this is what that cult was hoping would happen to them... I've heard stories of the titan under Guiston reaching out and 'touching' certain individuals, but I always passed it off as campfire stories." he says.
"If it's all true, Kallista will have incredible strength and abilities to do the titan's bidding." he says, then looks over the group.
"This changes things... we know Artimus is fighting alone; he's at the greatest risk. From what Aelar saw, lady Ashwa is also in terrible danger..." he reasons.
"Those are the immediate lives we could save, but if we could somehow clear the gates surrounding the Hawk's nest, the Guiston Watch could move freely through the city and start containing the Labors."

Fascinated by the sudden metamorphosis of Kallista and stunned into silence by their dilemna-Lazlo can only trust in the decisions of the group.  "I... I wish we could help everyone.." he says in a quiet voice.

Aelar looks a little hurt and confused that Kallista pulls away from him.  He just wanted to assure her that no matter what had happened, she was still his sister.  His friends were so often troubled by their inner demons and he just didn't always know how to help, or even if he should try.  He sighed.  He could only do his best.

"It seems to me that if we can stop the Labors by cutting of their power, that saves everyone at once.  There aren't enough us, and we just haven't gotten all that good with our skills, yet, to do much.  Well, most of us."  He pauses and then looks around, starting with Hyre.  "I know we've got little chance of helping.  But, for me, little chance is not no chance and I'd rather take that chance and live...or die...with the results.  But that's me.  I get others may have a different view.  I think we should try to help Mr. Grimbuld and the dwarfs.  If we can help them get to the Heart Chamber, they can cut off the power, isn't that right, Hyre?"

((Shall I bot Hyre? Anyone have objections?))

((He did say you could… I think yes. How much trouble could we get in?))

Hyre considers his words carefully.
"If we're going to take any risks, we should take the risks that endanger us the least, right?" he says.
"Mr. Grimbuld was fighting three or four Labors by himself, so we know what we'd be up against, but we don't know exactly how bad it is at the Dwarven Hearth. There could be dozens waiting for us there. Maybe it'd be best to help Grimbuld, then he could join the fight to save whoever is left at the Hearth. He sure seemed fast enough moving through the wilderness and scaling the city wall." 

Geoffrey looks to Kallista.
"How strong do you feel? Think you could take on a few Labors?" he asks.
"Not to mention, Grimbuld has his collection of powerful bows and special arrows that could help you all act from a safe distance. If we do it fast, we may be able to help a lot of people without losing anyone, that's my opinion."

((Kallista can't exactly explain how she does, but she has a full understanding of the powers she now possesses, even if control over them might be in question.))

Kallista nods.

”To Mr. Grimbuld, then.” 

Aelar nods, "Mr. Grimbuld it is."

The driver takes directions and the manta kite swoops closer to the city. It isn't long before the walls come into view, and the whole group can see that the majority of the chaos is indeed happening in the Nest. The farmlands, the Ritz, and the Warren are relatively unaffected, but there are multiple fires out of control towards the gates. The alarm bells are still tolling as the Guiston Watch tries to find a way into the Nest past the gates.
Grimbuld's shop is halfway between the Warren and the Nest, which is probably why he ran into more trouble.
Grimbuld's condition: 41

 When the manta kite comes to a stop above Grimbuld's shop, the great beast refuses to get any lower than the rooftops of the 2 and 3-story buildings. The group will have to climb down as best they can; or, they can wait to see if Raia can cast any more spells, but it would be faster (though riskier) to pass a DC 14 Athletics check(Kallista doesn't need to bother, obvs.) which will count as a success should you succeed, but fail by more than 5, and your character will take 1D6 fall damage unless they're caught by another ally, which will be a reflex check of DC 16.
Grimbuld isn't anywhere to be seen from this angle, but the metallic braying of the Labors can be heard from inside the smashed front window of the shop. Grimbuld is still under attack somewhere inside.

There is blood spatter all around the front of the store. It looks like something was dragged inside, over the smashed glass.

ooc: Do you mean jumping down to the roof of the buildings or to the ground?

“Here we go… one hoof in front of the other, hand over hand and try not to look… down…” Lazlo gulps. 
Athletics 13.   
Reflex if anyone falls 20

Graceful he is not.

Aelar reaches out to grab Lazlo.

Reflex (Dex) 22

"My turn," the elf says as he leaps down.  He acts brave but his friends hear the quaver in his voice.

Athletics 3