Ten years ago...
"What do you mean the yiga clan has infiltrated the city? If I recall, any and all mining operations have already been suspended. What could they possibly gain from this intrusion?"
"I'm not sure what they're doing, Guster. Their robes should catch fire amidst the extreme heat, but they're still here regardless. Perhaps they got a hold of some fireproof elixirs? That's the only explanation as to why they're not burning up right now."
"Whatever the case, we have to act now. I won't allow those fiends to take this land."
"Are you sure you're ready, gramps? Ha, I don't think they let old coots on the battlefield anymore."
"As your leader, I expect to hear: roger, we'll prepare our forces for an all-out attack."
"The day I say something so dim-witted is the day when cuckoos fly. Sorry, gramps, you might be pretty sharp, but you've definitely lost your luster. You use to conserve your forces; now you just throw them around willy-nilly. You're a shell of your former self, a far cry from the Goron you use to be. How could anyone ever respect someone who's fallen that far from grace? Plus, war is a young man's game; even rookies know that."
Guster sighs and digs for his magical staff through a thick pile of junk. He uncovers the dusty heirloom, ready to make good use of it, "It's been a long time since I've had to use this baby. I can tell she's yearning for a good fight."
The Goron tribe confront the yiga clan on a large plot of scorched soil. Leading this unruly cavalry is a woman adorned with a straw hat. Once Guster spots this intimidating leader, he makes haste to the front lines.
"Hey, don't push!"
"Oh no, here comes that old geezer. How's he gonna screw us over now?"
Guster readies his wand, "State your purpose, fool, or I shall banish you from once you came."
"I mean no harm; I'm simply enjoying the serenity of the mountainscape."
"Pfft, this land is anything but serene."
"Even if that may be true, you can see how I arrived at that conclusion. From the laid-back locals to the soothing springs, anyone would assume this area to be nothing more than a vacationer's paradise."
"As an accomplished mage, reading auras has almost become second nature to me. I can assure you that no black-hearted tourist will ever set up camp upon my mountain."
"Huh, a mage, you say? How's about we go one on one? You have an awful lot of gusto for someone your age. I wanna see if your words hold any weight to them," Rubaru challenges.
"I hardly see that as beneficia-"
Rubaru provokes Guster by unleashing a torrent of swift-moving knives at him. Guster lifts a wall of rocks from the ground to deflect the oncoming projectiles.
Rubaru approaches Guster with her tempered blade.
"Why endanger our own lives when we have troops who will do just that?" Guster pleads.
Rubaru then speeds towards Guster, beckoned by her devotion to the craft. Guster launches sizeable stones at Rubaru while moving backward. Rubaru splits the stones with her trusty katana, continually gaining ground on Guster.
Guster erects a pillar of rock from beneath Rubaru's feet, "We are generals, not expendable soldiers. The very survival of our army hinges upon us."
Rubaru slides down the column using her katana. Guster flings stalagmites at the descending Rubaru, hoping to knock her off her game. Guster then separates the cylindrical column from the ground. Rubaru jumps off the crumbling tower, releasing a frenetic slash downwards.
Guster's staff shimmers, and he covers his body in rocky armor.
Guster punches upwards as Rubaru slices downwards.
The two gladiators cross paths...
A moment of silence permeates the area.
Rubaru is the first to fall.
Guster approaches the collapsed warrior with a faint level of hesitation. He was still unsure of how many tricks she had stuffed up her long silk robes.
"Impressive, it looks like all that gold does glitter. But anyone can have guts; grit is what really matters," Rubaru says, scurrying into the crowd and placing Guster's second in command a dangerous bind.
The Goron's ready their weapons in response to Rubaru's impulsiveness.
The yiga follow suit, quick to match the other side's fortitude.
"What are you ugh doing?" Guster asks, holding his sternum.
"I'm taking the necessary measures to ensure my safety. If you let me go, his neck remains bare, but if you attempt to pursue me or my forces, there's a good chance it'll be soon drenched in the color of my flag."
"Gramps, you gotta listen to her. It doesn't look like she's bluffing."
She corroborates his claim by firmly pressing her blade against his throat.
Guster cuts his losses and tells his troops to stand down. He also removes the glowing stone from the end of his staff in an effort to appear less threatening.
"As expected, I'm in the presence of another cowar-."
Guster then hurls the jagged jewel at Rubaru, with little concern of where it ended up. She stands there, astounded, as the speeding bullet whizzes past her.
Not long after, she drops the desperate act and lets the hostage go, "It seems you've passed my test and with flying colors no less."
"What?"
"Not only have you proved to be a worthy adversary, but you've shown how capable you are at taking calculated risks. I believe anyone who can make tough calls under pressure is worth my time."
"W-what was that, Guster? You could've killed me! Why would you ever do something do so reckless? Jeez, I really thought I could instill some morals in you, but it looks like I was just wasting my time."
A peeved Guster faces the ghastly maiden, "Go on, you've intrigued me."
"Soldiers disperse! Meet me at the rendezvous point. We wouldn't want our new allies to feel threatened."
Guster holds a meeting with Rubaru at the peak of the mountain.
"Now that we've gotten the introductions out of the way. Why are you here? And don't try to dodge the question. If you have any dignity, you'd reveal your true intentions. Oh wait, I forgot you're a yiga. Scoundrels like you don't have the spine to spill your secrets," Guster reasons.
"I'd beg to differ. Our spines may not be as straight as an arrow, but they certainly are there. Sturdy too. That's why I changed sides. I saw potential in these bumbling greenhorns."
"You switched allegiances!? How could you do that to your brothers in arms? Where's your loyalty, your integrity, your burning desire to pay tribute to your lineage?"
"Why should I honor those that only barely give me the time of day? Why should I honor the people that laugh in my face and spit in my food? People that ostracize me based on the values I hold dear."
"Hmph, I guess I'm not the only one?"
"If you really want to know why I'm here, I'll tell you. Unlike most, I know a good strategist when I see one. And I feel if I nurture our connection, it could possibly blossom into some special. My people and I were sent here to retrieve a mystical flute. The legends say the flute is supposed to be held at a locale called the Igneous Cave. We didn't have much to go off of, but considering the Eldin region is covered in fire, it was worth a shot to look here. Master Kohga just wants the flute as a decorative piece. But I have bigger plans; I want to use it to overthrow him so I can take up the throne. If only I could get my hands on that flute, then I would be able to cause all sorts of carnage. And I mean carnage. Don't let their simple composition fool you. Those melodies can turn the world upside down in seconds. Just think about it, the power to freeze time, the ability to put people to sleep. You could even draw fire out of thin air; what's not to love?"
"As you can see, I'm not your run of the mill yiga. I'm a yiga with ambition, not bound by rules or customs."
"Join me, Guster! Together we could rule over the mindless fools that inhabit the yiga tribe. No, we could rule over all of Hyrule."
"Rule? All I desire is respect."
"People are meant to be ruled. If not, who would tell them to fall for their cause?"
"Yeah, those kids don't understand that in the heat of the battle, your gonna have to make hard choices. Casualties are only necessary to achieve the desired outcome."
"Guster, I can give you an army that will put their lives on the line for you. An army that will follow you to the ends of the earth with no resistance."
"As persuasive as you are, I'm not just going to leave my tribe on a whim. I have a duty to uphold, you know."
"Yeah, a duty to make the decisions nobody wants to make. But no one respects that. No one seems to acknowledge your plight. The only thing people thank you for is the blisters on their feet."
"I would like to take you up on your offer, but how could any self-respected leader ever abandon their people? And working for the enemy, that goes directly against the Goron code."
"I'm not twisting your arm here. You're in full control of your destiny."
"But aren't you tired of being pushed around? From what I've seen, you aren't the happiest being here. Being treated the way you do, being pushed around because everyone thinks you're too senile. I sense greatness in you, Guster. I sense strength. Once I overthrow that imbecile, Master Kohga, we'll be practically unstoppable. We'll carry the rage of ten thousand suns, willing to take out anyone that has done us wrong."
Guster sighs, plagued by uncertainty, "I don't know; I promised my nephew that I was one of the good guys, a true hero till the end."
"Oh, silly Guster. Everyone has a role to play in life. Some people play the heroes, the brave and noble, always aiming to make the world a better place. Some people play the villains, the selfish and greedy, always attempting to wreak havoc on poor unsuspecting citizens. Some stay within the confines of their respected roles for their entire existence. But most, and I mean a very high percent, tend to ride the line between good and evil."
"We can ride that line; we don't have to be considered villains," Rubaru urges.
"Wow, that's a good lesson to live by. Who told you that?"
"No one, I figured it out by myself."
Present Day...
The sound of ambient waves gives Guster the assurance to finish his writings. As his feather pen leaves the parchment, he skims through the note once again.
"Dear Rubaru,"
"It's been ten years since we've met. We've had some highs and some lows, but overall it was a positive experience. We even successfully overthrew a powerful dictator with just our wits alone, not to mention the aid of a well-placed banana."
"That's why it pains me to say this. But I'll be taking my leave of absence as of today. I'm retiring. Life's too short to be dressing up in costumes and playing heroes and villains."
"I know you still desire my presence on the battlefield, but you will have to continue on without me. I'm starting to lose my dexterity anyways, so it really wouldn't be too big of a hit for you. But I wish you and your band of thieves the best of luck."
"Speaking of family, I recently saw my nephew. Considering all the people I've cut ties with, he's practically the only family I have left. I never imagined he'd get so big, so full of promise, radiating confidence like it was my brother in the flesh. I know I may be letting nepotism get the better of me, but seeing him and how much he's grown—seeing him finally become a man right in front of my eyes. Well, it makes me realize that I need to grow up too. I need to stop being so immature, flip-flopping sides all the time. I need to stay on the side I was born into. And that's being a hero."
"My deepest regards, Guster."
Guster folds up the paper and seals it. He then attaches the letter to the foot of a rainbow pigeon. After the bird takes off, Guster looks into the calming mid-day sky.
"Good luck, Gustav. You're gonna need it."