There was an order of operations among the Bearers: when there was a problem, you went to the most capable other Bearer in that area and worked your way down. You had an issue that needed intelligence? You went to Twilight first, then probably Pinkie Pie (who knew far more than she let on), and down the line until you got to Rainbow Dash and you knew you were in trouble. Similarly, if you had a technical problem you started with Applejack and worked your way down to Rarity (who was usually too distracted by surface issues to solve the underlying problem.) Non-Bearers were only involved when none of the six could handle things - that was an unspoken bond between them, because no matter what? They had a connection that transcended competence. They had faith that their best friends would come through.
There were exceptions, of course - Applejack went to her family just as readily and Fluttershy had Dr. Fauna because she wasn't going to mess around when an animal's life was on the line. Spike was also in the mix, but irregularly: they all recognized he was very capable and knowledgeable, but he was also a child and that was an extra layer of reluctance to involve him when you didn't have to. (Rarity excepted, which everypony else still was quietly displeased with.) But those outside allies were fairly specific, and you wouldn't see Rarity going to Dr. Fauna for help without Fluttershy, nor Twilight asking for Granny Smith's aid without Applejack. By these rules, Starlight Glimmer 'belonged' to Twilight Sparkle, and would only be approached with the Princess of Friendship's help.
So when Rainbow Dash came to get Starlight Glimmer in the dead of night alone, it was a signal that something had gone very, very wrong.
"Starlight, you know crime, right?"
This was also a bad sign.
Starlight very carefully considered her next words. "Why do you think that?"
The response was not so carefully chosen. "I mean, you and Trixie–"
Starlight's magic clamped Dash's mouth shut in a panic. "Okay, okay, I get why!"
A light smack to the unicorn's horn disrupted the spell so Dash could talk again. "Look, I need a lawyer and I figure - you know crime, you're good at manipulating ponies, you're the perfect choice!"
Alarm bells continued to go off in Starlight's head, but were overwhelmed by her unending lack of amusement. "You're really bad at getting ponies to help you, Rainbow Dash."
"Well I don't need help often, because I'm awesome."
"Urge to help you diminishing rapidly…"
Panic flashed in Dash's eyes. "But not awesome enough for this! Please Starlight, you gotta help me!"
For a moment, she considered refusing Dash. But Twilight's lessons had dug too deep and Starlight knew in her heart of hearts that she could never truly say no. Not in the face of such desperation. "I'd like to help you, Rainbow Dash, but being a lawyer requires more than just knowing crime and being able to convince ponies. I don't have a law degree or a license, and without those I can't practice law in Equestria."
Briefly, Rainbow looked distraught - right up until those last words. "Oh! Then it's all good, because the case isn't in Equestria."
New dread set in. "You committed crimes in Griffonstone?"
"Not... exactly."
Ponies in general were used to the Bearers being involved in ridiculous shenanigans. They regularly interacted with previously unknown creatures, got into situations that defied all sense, and had proven more than a few legends to be real. Starlight - being Bearer-adjacent - had an even greater tolerance than average for the weirdness. But even she had to pause a little to wrap her head around the oddity of what was before her.
The courtroom, it turned out, was not in Equestria. It wasn't really in anywhere. The featureless white void of Limbo stretched around them for infinity, rending the mind of mortals with the sheer scope of the unending. The existence of a courtroom - or at least the judge's bench, a witness stand, and two tables for the plaintiff and defendant respectively - actually hurt more than it helped because it gave context to the vast infinite.
Starlight tried to just focus on the papers in front of her and not think about what was (and wasn't) around her. All that mattered, she told herself, was Rainbow Dash (sitting beside her), the judge (behind the bench), and the opposing attorney (at the opposite table.)
The judge in question - an autumn-colored deer creature made of leaves - adjusted his pince-nez glasses. "Now hearing Rainbow Dash, Spirit of Hearth's Warming versus The Grand Council of Holidays."
"Objection!"
Starlight shoved Rainbow Dash back into her seat.
Both the judge and the opposing counsel (a windigo wearing a bow tie) looked disdainfully at Starlight, who tried to smile past her embarrassment.
"Rainbow Dash, Spirit of Hearth's Warming versus The Grand Council of Holidays," repeated the judge with far graver authority. "Judge Great Seedling presiding." He rapped his gavel. "Miss Glimmer, do you have an opening statement?"
"I do, Your Honor." She rose, moving around to stand before the bench. "While the circumstances of Rainbow Dash's ascension to become the Spirit of Hearth's Warming were both extraordinary and tragic, I will demonstrate that the role must be given to another. While she does indeed have the qualities needed to embody the Fires of Friendship and the spirit of the season, it is a mantle that she cannot take up. I sympathize with the members of the Grand Council of Holidays, but they sadly need to find a different being to carry the torch going forward."
Judge Seedling nodded - then turned his gaze to the other side. "And Miss Maria, for the defense?"
The windigo stood up (at least as well as one could with no rear half of the body) and - after adjusting the bow tie - opened her mouth. A horrible cacophony rattled forth: the sound of ice and death, carried by cruel winds that cut through coats like a blade and snuffed out even the concept of heat. It continued for several seconds before the windigo paused, cracked open a tin of breath mints, chewed one, and cleared her throat. "Ahem. Apologies, Your Honor, I'm getting over a bout of the flu." Judge Seedling nodded to accept the excuse and she continued. "The Grand Council of Holidays will show that Rainbow Dash, through her direct actions, caused the deaths of all three prior Spirits of Hearth's Warming–"
"You killed them?!"
All eyes went to Starlight Glimmer as she verbally exploded at her 'client'.
Rainbow Dash shifted in her seat. "What? No. No way. They were just, uh. Just stunned!"
The windigo Maria glared. "You crashed into them at maximum speed, killing all three of the Gift Givers instantly."
"Okay, first of all," Dash shot back, rising out of her chair in anger, "That was nowhere near my top speed and I demand the court records reflect that! And second, I didn't crash into them! They were just near the part of the ground I crashed into!"
"Inside the blast radius," Maria pointed out sneeringly.
Judge Seedling banged his gavel. "Order! ORDER! Testimony and statements will be done according to the book, NOT shouted out randomly!"
Starlight grabbed Rainbow Dash and pulled her back down. "Dash, I swear to Celestia I will quit and let them force you into indentured servitude delivering gifts for eternity if you don't stop making my job harder."
Across the aisle, Maria adjusted her tie and returned to her planned statement. "As the effects of the impact are irrefutable hard evidence, there is no argument nor any wiggle room about the status of Rainbow Dash. By the Rule of the Clause, any being who causes the death of a Holiday Spirit must take up that Spirit's role as penance. While I am sure the plaintiff's counsel will try, no mortal argument can change the laws of the universe."
The windigo sat down - and Starlight glared daggers across the way. She had been challenged.
Judge Seedling turned to Starlight. "The plaintiff may call her first witness."
"The plaintiff calls Princess Celestia, Sol Invictus and Avatar of the Sun."
There was a flash, and indeed Princess Celestia appeared on the witness stand beside the judge. She was calm and collected - just as she had been when Starlight had briefed her on the situation. Judge and Princess gave one another a respectful nod, then the Judge motioned for Starlight to begin.
Eyes closed, she took a deep, steadying breath. Time to break the laws of the universe again. "Princess Celestia, could you please state for the court what your relationship is to the Grand Council of Holidays?"
Celestia straightened her back and started into the testimony they had discussed. "I am an adjunct member of the Grand Council of Holidays, representing the Summer Sun Celebration."
Starlight nodded. "And when you say adjunct member, what does that mean?"
"It means I was denied a seat on the council itself, but I am allowed to be present and have a non-voting voice in holiday related matters."
Take it slow, Starlight thought to herself. Don't rush. "Can you elaborate on why you have been denied that seat?"
There was a moment of hesitation from the Princess - they had gone over her testimony several times, but this was still an obvious sore spot and it took effort for her to keep her tone even. "Well, it traces back to the beginning of the Celebration. Traditionally, Spirits of the Holiday appear after the holiday itself comes into existence. A Spirit cannot exist without its holiday and they're tied together on a metaphysical level. But the process was in reverse for myself and my holiday, as I existed beforehoof and the holiday was created around me. Since I'm not tied as directly to my holiday, the other Spirits don't consider me a full member of the Council."
More nodding, giving a pause for dramatic effect. Starlight's eyes went for a moment to her opponent - but found no usable reaction from the windigo. "Is this a common situation, Princess?"
"No." Celestia's voice dipped deeply into bitterness. "I'm the only one. In fact, they denied my sister a similar place in regards to her own role with Nightmare Night."
"Denied on what grounds?" Starlight mentally kicked herself - she had responded too fast, almost snapping. She needed to stay professional, more so because Rainbow Dash looked ready to start throwing punches.
Celestia's response was slower, perhaps because of Starlight's overeager speed. "Well, they changed the rules. After my holiday came to light–" She paused to airily laugh at the pun. (No one else did.) "--There was a lot of debate on if I should be there at all. Eventually they decided on my adjunct position as a compromise, but rewrote the rules that only those who dedicated their entire soul to being a Spirit could fill the role. So my sister cannot join the Council as she has her ties to Equestria and to the Moon, with Nightmare Night being only a small part of her portfolio."
Another nod from Starlight. "Thank you, Princess. No more questions, Your Honor."
Judge Seedling turned to Maria. "Defense? Your witness."
The windigo hovered up slightly. "Just one question. Princess, as you obviously know the rule banning Spirits of the Holiday who are not soul-bound to their holiday, can you tell me: does the Rule of the Clause interfere with it when a mortal is forced to assume that role?"
For a moment, Celestia hesitated. "It does not." But not for long, because she knew the answer by heart. "According to the rule, a mortal who is forced to assume the role of a Spirit of the Holiday will surrender their earthly connections to become that Spirit properly. Doing so is part of the penance."
"No more questions, Your Honor."
Judge Seedling made a small motion with his hoof, and Princess Celestia poofed back out of Limbo and into the point of reality she had left from. "Next witness, Miss Starlight?"
Vicious glee crept into Starlight's smile. She couldn't help herself. She'd set things up and now it was time to spring the trap. "The plaintiff calls the Tree of Harmony as a witness."
For just a moment, the Tree of Harmony itself appeared on the stand. The tree proper was dwarfed by its root system: a nearly endless complex of crystalline tendrils that stretched beyond the horizon, enveloping the lands of Equestria, had dirt been there. Then the entire mass contracted into itself with a quiet vworp and condensed into a semi-translucent copy of Twilight Sparkle. "Hello."
"Hello, Tree." Starlight waved.
The Tree did not wave back. "Please return me. This is unpleasant."
Judge Seedling shook his head. "I'm afraid we need your testimony first."
"I am the Spirit of Harmony itself and I have been separated from my land and my people. I do not understand how you have uprooted me but I cannot remain." The Tree's tone never changed, remaining even and emotionless throughout. "This place is an anathema and every moment here is agony."
The Judge adjusted his glasses nervously. "We'll make it quick."
Starlight Glimmer stepped around her table. "Tree, the court will put you back as if you never left, but I need you to answer a question for me first. I'm sorry, but it's important."
The wide, doe-eyes of Twilight Sparkle looked back at Starlight with the deep, soulful expression of Maud Pie. "I trust you, Starlight Glimmer. Ask your question."
For a moment, she hesitated - that the Tree of Harmony was expressing trust in her made Starlight's heart soar. But no. She had to focus. The best way to pay the Tree back for the compliment was to get it home as quickly as possible. "Tree, I want you to tell me about the mare sitting behind me - Rainbow Dash."
Something in that clicked with the Tree. Its avatar sat up straighter as it noticed Dash sitting there, and an actual smile came to its face. "She is Loyalty."
"You mean she's the Bearer of Loyalty," Starlight leadingly corrected.
"She is Loyalty," the Tree reiterated. "To Bear the virtue is to be it. One cannot put it down once it is lifted. She is inexorably tied with it, now and forever. It is her, and she is it."
The noose tightened, and it took a lot for Starlight not to grin at her opponent. "So she can't retire from being Loyalty? She can't give up her Element and let somepony else carry it?"
The Tree shook its head. "To retire from actively representing it is possible and another may lift the virtue as well, but that does not change her being. She cannot retire from being Loyalty any more than she could retire from having lungs." It paused, momentarily pondering. "Those are obligatory for ponies, correct?"
"Very," Starlight noted.
"Then my metaphors are improving." The Tree sounded quite proud of that fact.
"Your Honor," Starlight began as she turned away from the witness stand, "This provides the core of my case: by the Grand Council of Holidays' own rules, a Spirit of the Holiday must dedicate their entire soul to the duty. But Rainbow Dash cannot do that, as her soul is already permanently and irrevocably linked with that of one of the Elements of Harmony. While they may try to invoke the Rule of the Clause, they have no right to sever another cosmic entity's connection to Rainbow Dash and thus cannot force her to serve as the Spirit of Hearth's Warming without violating the Grand Council's own rules."
Before the Judge or the defense could respond, however, the Tree of Harmony raised a hoof. "Excuse me. Am I correct in understanding that this is about the Grand Council of Holidays attempting to induct Rainbow Dash against her will into their membership?"
"It is," Starlight confirmed.
The Tree nodded. "Understood." And the avatar's head turned to look at Maria. "Keep your filthy temporally-bound claws off of my stuff, or I will snuff out every last one of you and replace you with a new set of holidays that are more adept at respecting their betters."
An icy chill passed over the room that wasn't the windigo. Judge Seedling cleared his throat. "Er, yes, let's just… thank you for your time, Tree of Harmony."
"I am Loyal to Loyalty, and gladly serve at her side," the Tree pronounced. And then it blipped back to its proper place in reality.
Behind the plaintiff's table, Rainbow Dash shivered. "So. Cool."
Unsteadily, Maria rose at her table. "In light of this evidence, the Grand Council of Holidays feels that it is in everyone's best interest to make an exception in the Rule of the Clause and allow Rainbow Dash to not become the Spirit of Hearth's Warming should she so choose."
"HA!" Rainbow Dash leapt up and pointed at the windigo. "IN YOUR FACE!"
Starlight's magic shoved the pegasus back into her seat. "Shut up, Dash."
Judge Seedling banged his gavel again. "In that case, I find in favor of the plaintiff, Rainbow Dash. Case closed."
Starlight Glimmer and Rainbow Dash hugged. "You owe me," hissed the unicorn into her now former client's ear.
"I do." Dash, at least, didn't deny that. "Trust me, I owe you big time for this, Starlight. And I'll make sure everypony knows how great you were and how much you helped me."
Three months later, Starlight was awoken in the middle of the night by a knock.
Opening the door, she found Fluttershy there - without Twilight Sparkle, but with a basket of brightly painted eggs and wearing a rabbit costume. "Um, Starlight, I'm very sorry to disturb you but, um, I think I may need a lawyer."