After the Inquisitor had left, Suyin asked Kuvira who he was. "The Inquisitors are Force-Sensitive agents of the Empire," Kuvira answered. "They do the little things that Darth Vader can't waste his time with. In this case, teaching more of our people on how to use the Force the way they do."

"What else do they do?" asked Opal. "The term 'Inquisitor' sounds a little like Investigator."

"They spend much of their time hunting Jedi fugitives and other Force-Sensitive criminals," Kuvira revealed. "Specifically, exposing how they have such power." Suyin felt a little unnerved at that description. It sounded reminiscent of nosy moral crusaders or secret police. "Vader is far more powerful but he can't be everywhere, and not everything requires the biggest hammer in the toolbox," Kuvira continued. "That lightsaber the Inquisitors have: that's not a handguard. That's a rim for the emitters to spin across like a buzzsaw. They use that gimmick to frighten people into surrender. Of course, some people won't be frightened, so they still know conventional sword fighting." Kuvira's family was surprised to learn the reason for the shape of the Inquisitor's hilt but then again, they'd never seen a handguard of that shape before.

"So, what's his species called?" Suyin asked.

"Pau'an, from Utapau, where they are the administrative caste above the Utai, a bunch of squat, bulbous-eyed, brown-skinned laborers," Kuvira answered. "But from what I gather, the Inquisitors, regardless of species, are a bunch of humorless, small-talk despising workaholics. When on the job, they don't call each other by name but stuff like 'Seventh Sister' and 'Fifth Brother.'"

"Is there a contest among the Imperials over who can be the most creepy?" asked Bolin, unnerved by this further information.

"I don't know, Tarkin might start one," Kuvira joked back, before looking at Opal. "But then again, given how Pau'ans think cooked meat is poisonous, he might be terrified of our dad's barbecue." Suyin and Opal chuckled at that, remembering how, even on Elementia, there were people with bizarre customs, and pushed the frightening talk of Inquisitors out of their mind. Kuvira then unlocked a box and pulled out a black, pyramid-shaped crystal from within.

"This is the holocron which taught Bolin and Ghazan Lavabending, and Yakone daytime Bloodbending," Kuvira revealed, handing it to Su. "I want you to know the ways of the Force. If you can unlock it, you are capable of learning from it."

"Thank you," Suyin said to her adoptive daughter, appreciating this gesture of trust. "How do I unlock it?"

"It is hard to describe," Kuvira said. "A bit of the right mindset, eagerness to strengthen yourself, and then opening your mind to the wider world. But whether you have the power to open it, and unlock the knowledge within, is something only you can find out. It's like whether you are tall or short: either you are born with this strength, or not."

"Makes sense," Suyin replied. "Tenzin tried his whole life to connect to the Spirt Realm, and failed every time, while Jinora tried when she around fourteen and succeeded immediately." Su hugged her daughter, and said they'd see each other soon, after she accepted Opal and Bolin's ride back to Zaofu on her Sky Bison.

"Hey, I'm just wondering," Opal asked her big sister. "Could you get in touch with some of those cloners? It'd really help bring the Sky Bison, and Dragons for that matter, back from the edge of extinction."

"I'll see what I can do," Kuvira smiled. "Love you guys." With that, Suyin and the others prepared to depart, while Kuvira wondered what new power the Spirit Vines could provide.


After Greez joined them in the Prefab, Cal started his own tale about how he'd hidden in a scrapyard as a salvager until an Inquisitor found him. "What's an Inquisitor?" Luke asked, being rather unfamiliar with the Empire's branches.

"They are a bit secretive even in the wider galaxy," Greez said. "They are Dark Side-using Imperial agents who hunt Jedi and other Force Sensitives. They have tacky, spinning lightsabers that, if you don't let it dazzle you, are, if anything, their greatest weakness. Since Vader and Palpatine don't want their minions to rival them, they rarely have more than those gimmick sabers and basic force powers. After all, their main job is hunting Jedi children who survived because they were lucky, never having the opportunity to continue their training, and guys who were never trained at all, presumably because they are kids around your age or younger, too young to even remember the Jedi, let alone be taught by them."

"There is no such thing as luck, but the description is more or less sound," Obi-Wan added.

"Oh, I would say luck is very real, Master Kenobi," Cal disagreed, before Luke asked a question: If the Sith in charge of the Empire wanted to stop any other Force Sensitives from opposing them, where did the force-using Inquisitors come from?

"Some are among the untrained, who Palpatine reached and decided to use," Cal began. "But most of the one's I'm aware of were Jedi, captured by the Empire, and tortured until they turned to the Dark Side, embracing the Empire."

"That makes no sense," Mizuki spoke up. "Torturing someone isn't a good way to inspire loyalty or belief in your cause, much less join you full time."

"Well, that's the theory-""Not theory, fact," Mizuki interrupted Cal. "During the Hundred Year War, the Fire Nation attacked the Southern Water Tribe relentlessly. They captured many Waterbenders, and imprisoned them in special jails where they were denied Water unless their hands were bound as someone else gave them a drink, on top of random beatings and supposed 'experiments' by doctors there. One of them, Hama, realized that, during a full moon, she could bend the blood of someone else, and used it to escape."

"Okay, what's the point?" asked Merrin.

"She hid out close to a village, where she began kidnapping, imprisoning, and ultimately murdering random Fire Nationals in imitation of what she'd endured," the Fire Princess explained. "When Grandpa Aang and Grandma Katara found out, they tried to stop her, to which she tried to kill them, along with Katara's brother Sokka. Torture certainly made her a worse person, but that's not the same as 'oh, I'm going to help my oppressors in their conquests and fight my own people, because their enemies have whipped me a lot.'"

"I'm guessing they never gave her the opportunity to join them," Obi-Wan said in response to her story. "The torture the Inquisitors employ is less about intimidating their captives but convincing them that the Light Side has failed, and the Dark Side is stronger. The torture only stops when they use the dark side to break free, then they are beaten down before they can escape, and given the option of joining or execution."

"Sounds like a good way to surround yourself with people who hate you and might team up against you so they are less afraid of challenging your power," Luke commented, also skeptical of what he'd heard.

"Inquisitors usually operate alone, and are encouraged to distrust each other," Cal said. "They can't rely on anything except themselves, which means they are alone against Vader if they challenge him. As such, any hatred they have will be trumped by their fear of him. Also, given how Vader has killed multiple Jedi on his own, their relatively meager skills might not be enough, even if they did team up." Greez also mentioned how the Inquisitors had their own group of Stormtroopers, Purge Troopers, made up of the most fanatical and bloodthirsty Imperial soldiers in black armor, red eye lenses, and skilled in lightsaber-proof melee weapons.

"Cere and Greez had picked up an Inquisitor signal at Bracca, so they followed it, and got me out of there before the 'Second Sister' could kill me," Cal said, continuing the story of his journey up until then. "Then, they took me to an obscure world called Bogano, where Cere's master, Eno Cordova, had hidden a Jedi Seeker device inside an ancient vault built by the Zeffo." Obi-Wan was surprised to hear such a device had survived.

"It's a combination of the Force and Technology," Obi-Wan explained for their young friends. "It points Jedi in the direction of new Force Sensitives born in the galaxy. I found the only one in existence in the Jedi Temple, smashed to pieces, after Order 66."

"Master Cordova hid a spare a few years before the Clone Wars, leaving his trusty friend, BD-1, to guide a Jedi on the journey to the vault's keys," Cal explained, patting the small droid on his shoulder. "It took me to the Zeffo homeworld, now just called Zeffo, Kashyyyk, and finally, Dathomir. Which is where I met Merrin and helped her defeat Taron Malicos."

"Was Malicos an Inquisitor?" asked Luke.

"No," Cal clarified. "He was a Jedi broken by the destruction of our order, who fled to a world all else avoided, and gave into his despair, and eventually, the Dark Side." He then mentioned that he had to go to Ilum, an icy world in the uncharted regions of the galaxy, to get new lightsaber crystals, as well. Obi-Wan clarified that Ilum was where many Kyber crystals formed naturally and was the sight of a Jedi pilgrimage fairly early in their training. "Of course, I'm not sure when we can go to Ilum, now, the Empire has really tightened security on its mining operations," Cal added, before Merrin said she could use her cloak to sneak Luke and Mizuki, there, if they really wanted to go.

"So, you managed to get the Jedi-finding device?" asked Mizuki.

"I did, and then I started thinking," Cal explained. "That the Empire ruled the galaxy almost unopposed and had thrown vast resources both into finding the Seeker and in finding Force Sensitives in general. Bogano was obscure, but not unknown, or hidden behind something. Sooner or later, the Empire would realize what I was doing, trying to train a new generation of Jedi, and find us. That is when the Second Sister, or rather, Trilla Suduri, arrived and stole the Seeker." At that moment, he decided to talk about Cere. After Order 66, she'd escaped with her apprentice and several Jedi children but had been captured. She was tortured into betraying her charges, where the children were murdered, and the apprentice was tortured until she became an Inquisitor.

"And Trilla was that apprentice," Mizuki realized.

"Yeah," Cal said. "They showed Trilla's fall in the hopes of breaking her, at which point Cere broke free, using the dark side, and escaped. When I met her, she imposed this quest on me, because she was afraid of using the Force after her failure to protect those students, and her brief use of the dark side. But at that moment, all bets were off, and she joined me in breaking into the Fortress Inquisitorius on Nur, a watery world in the Mustafar system. I defeated Trilla, and got the Seeker back, while Cere and I managed to break through to Trilla. And then Vader showed up and chopped her in half before she could commit to joining us. We narrowly escaped, and Vader stabbed me with my own lightsaber, right here." Cal lifted his shirt, showing a scar under his left ribcage. "I decided that the only way to really protect the kids the Seeker would find, was to destroy it."

"I think that was for the best," Obi-Wan said. "You'd already realized why it couldn't be used with the Sith ruling the galaxy, and as long as it existed, they could use it as well." Merrin went on to explain how they stuck together for a couple years, before Greez's arm was cut off. After that, Merrin went to explore the wider galaxy on her own, while Greez went to Koboh to set up a saloon, Cere went to find more Jedi relics, and Cal continued the fight against the Empire as a mercenary, so as to keep the Stinger Mantis in shape.

"You have to know when to walk away from a rigged game," Greez said, holding up his arm in front of Luke and Mizuki, showing why he briefly dropped out of the fight against the Empire. "I only got out from under the Haxion Brood because of Cere, and now, they've extended their grudge to Cal." Luke had heard of the Haxion Brood, a weird crime syndicate whose members liked to attach droid parts to themselves as cybernetics and assemble their own droids out of pieces from others. Apparently, they were headquartered in an asteroid station called Ordo Eris, whose main attraction was gladiator games.

"About five years ago, I assembled a new team and came up with a plan to learn classified Imperial information," Cal explained. "They'd pretend to be bounty hunters, then reach out to this senator who wanted to increase his station, saying they could deliver me, a Jedi Knight, to him. Predictably, his security amounted to a bunch of local CSF he bribed regularly and one KX droid, since he was basically usurping Darth Vader's responsibility, he couldn't use more official Imperial assets. On top of that, he'd decided to do the handoff in a run-down part of the Underlevels."

"It go to plan?" asked Luke.

"Yeah, and the information on Senator Sejan's yacht showed the Empire hadn't been slowed down even slightly by our efforts," Cal revealed bitterly. "Then, an Inquisitor showed up and killed the fool who tried to one-up her. While I managed to kill her, only one other member of my team, Bode, got out. The Mantis was damaged, so I went to Greez for help, on Koboh."

"Which began your quest for Tanalorr," realized Obi-Wan.

"Yeah," the redheaded Jedi confirmed. "I had to go to Jedha, where Cere had gone and joined up with the Anchorites."

"Is that what those weird monks with masks and funny hats are called?" asked Mizuki, remembering seeing a bunch of fully-clothed, masked people on the way to Cal and Merrin's house, with a series of decorations hanging from their hats, and a symbol which looked like a circular door opening on their chests. The way they carried themselves reminded her of the Fire Sages and Air Acolytes she'd seen on her homeworld.

"Yes," Cal revealed. "Master Cordova was also there, to BD's delight. And while they were helping refugees flee from the Empire, Merrin was there, fighting the Imperials as the Desert Ghost."

"I had returned from Dathomir, and learned some new abilities," Merrin answered. "Eventually, we beat our...competitors for Tanalorr, and that is when Cal and I became more than friends, during our celebration on Jedha. And then, Bode revealed the Anchorite sanctuary to the Empire, killing Cordova before fleeing with the map to Tanalorr."

"He was a spy?" a surprised Luke asked.

"Yes, and no," Cal answered. "I caught up to Bode, and for the first time in a decade, he used his lightsaber, tossing me off a cliff. Meanwhile, Merrin worked to help the Anchorites escape, and then Darth Vader arrived. Cere knew there was only one way for anyone to escape, in that situation." Luke was initially confused, and then he realized why Cere wasn't on Tanalorr as well.

"I am so sorry about your second master," Obi-Wan said, hoping that Cere's death wasn't one he could have prevented by killing Vader that very same year.

"Thank you," Cal said. "I followed Bode, not to the Inquisitorius, but to a hidden ISB listening post." Luke didn't know what that acronym meant, so Greez said 'Imperial Security Bureau, the secret police for regular people, like the Inquisitors are for Force Sensitives.' "I found Bode's handler, a paper-pushing schemer named Denvik," Cal continued. "Denvik thought that, because he played games of office politics with the other intelligence analysts, and cloak and dagger with Rebel cells, he could be a Jedi hunter."

"Bode doesn't sound like an Inquisitor," noted Mizuki. "And from how Greez said it, they were different departments."

"Bode wasn't an Inquisitor," Cal confirmed. "He was a Jedi Knight who worked at Intelligence instead of the battlefield during the Clone Wars. He escaped Order 66, met a woman, and they had Kata." The others tilted their heads, remembering how Cal mentioned killing Kata's father within the Tanalorr's temple, before he continued and explained that Kata's mother had been killed by Inquisitors looking for Bode. "Bode's strategy for survival, was to reach out to his old friend Lank Denvik for help," Cal continued. "Denvik gave him a safe place to put Kata and Bode became Denvik's personal agent for his private projects. But Bode had started cracking under all the pressure and had come to see Tanalorr as his and Kata's salvation. His inability to trust anyone ensured he wouldn't share Tanalorr with us. When he realized I was there, Bode set off the alarm to cover for his and Kata's escape, leaving Denvik to be strangled to death by Vader for trying to usurp him. But Merrin and I found our way to Tanalorr, regardless. We tried to reason with him, with Kata imploring her father to surrender, and he chose to fight, breaking that bridge which his daughter was standing on at the moment. I beat him, seemingly getting through to him, at which point he acquiesced. Then, when our guard was lowered, he pushed Kata away with the Force, wrapped his arm around me, and tried to choke Merrin the way Vader loves to strangle people. She tossed her dagger into his shoulder, allowing me to go for my blaster as he went for his. His short-circuited, and I shot him before he could do anything else." Obi-Wan remembered how dangerous emotional attachment could be upon hearing that story, even to the people you were attached to.

"It sounds like he was as big a danger to his daughter as he was to everyone else," Mizuki said, horrified to learn how terrifying someone's love could get for those on the receiving end. Luke himself was baffled at how such a positive emotion could be dangerous. "So, when do Luke and I join Kata for Jedi lessons?" At that moment, Obi-Wan asked to speak to Cal alone, as he was unsure of what to do in regard to Mizuki desiring to be a Jedi.


After landing the shuttle in the South Pole, Mako and Korra hugged her parents, and then went back to their house, while Vader went off in a different direction with Tonraq and Senna. Looking at their pets, and the guardian droid, Korra picked up her son, Harou, and his baby bottle. Mako saw that Saria was asleep, so he tucked his daughter into her crib. As much of an annoyance that Izumi had been, she hoped to return the Fire Lord's daughter to her, soon. Of course, Mizuki could have been taken anywhere in the galaxy, the Avatar didn't have the luxury of going across the stars until the Fire Princess was found. When Bumi and Kya found a viable lead, she and the other apostles would accompany Vader to handle the two Jedi and the 'Nightsister' that were out of the league of the average Bender. That is when a thought hit Korra, prompting her to kiss her husband and charge to where Darth Vader had gone.

"I'd ask you not get out of your armor, yet," she told her Sith teacher, who'd gone into his private healing chamber. "There is something I'd like your help with: killing Koh the Face Stealer. I've made sure to study the Face Stealer, and I know that the owl of knowledge, Wan Shi Tong, has the artifact needed to destroy him." Growing up, Korra had been told about the adventures of the past Avatars. They had fought many enemies, but the one adversary that truly scared young Korra was Koh the Face Stealer. An embittered spirit, he had taken to swallowing and imprisoning the souls of humans, allowing him the ability to wear their faces. He did this by making the humans show emotion on their faces. The last Water Tribe Avatar, Kuruk, had lost his love to Koh, who apparently took issue with Kuruk's lackluster attention to duty. Korra figured Koh had done so for fun, and might try to torment her, as well. She'd obsessively studied the Face Stealer, determined to find a way to kill him. Eventually, she learned of a magic dagger that could only be used once, capable of destroying a spirit in the Spirit World. But it was inside the library of Wan Shi Tong, who had taken his collection back to the Spirit World out of disgust Aang had sought to do something with that knowledge beyond preserve it.

After a moment, Vader agreed, knowing the spirit which absorbed the souls of mortals was a problem that needed handling.

"Can't this wait?" Senna asked her daughter. "You just got back."

"Koh disapproved of Avatar Kuruk, the last Water Tribal Avatar before me, and did his trick on Kuruk's wife," Korra answered. "I'm not waiting for him to play 'disapproving trickster' on me. As for Wan Shi Tong, he betrayed Jinora to Unalaq, the only reason I had to open the portal and release Vaatu. As such, there are only two ways this can go: either he gives us the magic dagger, or we kill him."

"Agreed," Vader stated, standing up. "We'll be back in only a few hours. I'll keep Korra safe, while we're in the Spirit World." Tonraq knew his daughter wouldn't be persuaded to wait, and given all the damage the two spirits in question had done, it would be a relief to know they were gone, like Vaatu. He made his daughter and brother promise to be careful, which they did.

"I love you, Mom, don't worry, I'll be fine," Korra assured Senna. With that, Korra and Vader headed through the Spirit Portal, and quickly made their way to Wan Shi Tong's library. After they entered, they were confronted by the giant owl.

"Avatar, you are not welcome in my domain," the knowledge spirit said, before turning to Vader. "Nor is your companion."

"Well, Owl-Knowing-One, perhaps you should change your mind," Korra said. "My friend, Darth Vader, comes from a planet far from ours, and knows much that you never dreamed of."

"I no longer care about the human world, or what lies beyond," Wan Shi Tong said. "And given how you destroyed the spirits last, best hope of balance, along with the last good human, Unalaq, my patience for your presence is limited, especially with your sacrilege against Vaatu." With that, Korra had enough, and, remembering Mako's lessons, shot a lightning bolt into the giant owl's chest. She tossed her two lightsabers at Wan Shi Tong's ankles, slicing off the giant spirit's feet, while Vader charged forward with his own lightsaber, slicing off a wing.

"That's for Jinora!" Korra yelled at the incapacitated spirit. "You thought you could betray her to Unalaq without consequence? Think again!"

"Korra, he's in pain," Vader said. "Stretch out with your mind and help me penetrate his defenses." Korra reached out with her telepathy, and while Wan Shi Tong's will was strong, he couldn't defend from both Avatar Korra and Darth Vader. Soon, they learned where the dagger, the one thing that could destroy Koh, was within the library. Vader then brought his lightsaber down on Wan Shi Tong's neck, beheading the knowledge spirit. Knowing that, in the spirit world, the spirit would reform if any of his pieces remained within, the Avatar and her Sith master levitated the pieces and carried them out to the Southern Portal. When they arrived outside, they ordered the Imperials outside to take the pieces into orbit and drop them into the atmosphere of the gas giant at the edge of the system. Captain Praji affirmed the order, and had the crew of the nearby Gozanti load up the pieces, on the double.

"Follow us back to the library, Lieutenant Jir, with a full scanning and documentation setup," Vader ordered the second officer. "Record everything documented in the library, no matter how seemingly trivial it appears."

"As you command, my lord," the Stormtrooper officer replied as the Gozanti lifted into the sky, assembling his team with their documentary equipment before following his superiors into the Spirit World. After leaving their subordinates at the library, Vader and Korra headed for the lair of Koh the Face Stealer. As they approached, Korra saw a familiar face, Iroh I, who she'd briefly met during her fight against Unalaq and Vaatu.

"Avatar Korra, it is a pleasure to see you again," the elderly ghost said to her in his warm voice. "Many were afraid you'd never return."

"Indeed, nice to see you too, but I'm a bit busy at the moment," Korra replied as she continued on her way.

"Your self-imposed quest can wait," Iroh said. "There is a great imbalance in your spirit."

"No, there is simply something you don't understand," Vader cut off the famed philosopher. "Specifically, a power from another world. I am teaching Korra to master it, like I have." At that moment, Iroh looked at the Sith Lord, finally acknowledging him.

"I observed your first visit to this world," Iroh said. "As a boy, I wondered what might live amidst the stars, and I was surprised to see that it was filled with the...familiar," the ghost said, sounding somewhat reserved when saying familiar. "Looking at you, I'm not sure if you have mastered this power, or if it's mastered you, Darth Vader."

"You can't be sure of many things beyond this planet," Vader dismissed, before turning to Korra. "Let's handle the abomination within." As they walked into the lair, Iroh said that Vader's mask wouldn't protect him from Koh's power.

"Ah, another Avatar," a creepy voice said. "And an outsider, as well. Your mask won't protect you." Vader made a point of showing emotion under his mask, and he felt a strange pulling sensation. It was strong, but Vader was stronger, and soon, ripped off one of the faces that had been stolen, a woman's, freeing her soul in the process. Soon, Vader grabbed onto the abomination known as Koh, ripping off one face after the next, with Korra holding the centipede-like monster in place, using the Force, until only his true face was left. It looked like a clown's, Korra thought, entirely white, red lipstick, and circles painted on the eyes.

"How can you do this?" the ancient monster asked in disbelief.

"There is a stronger power than you, in the universe," Vader said, reaching out with the Force to see within Koh, confirming there was only one soul left. "It's time to end your reign of terror." Korra took out the dagger she'd retrieved from Wan Shi Tong's library and stabbed it through the monster's mouth. Soon, Koh began shaking uncontrollably, screaming in pain, with his body expanding. Then, a golden glow appeared, and he disintegrated into a cloud of gold dust. Vader and Korra could feel the shift in the Force as Koh finally died, with the lair of the abomination fading away as well, with Iroh outside, looking amazed.

"I...didn't think it could be done," the elderly Firebender said. Before he could say anything else, Korra and Vader saw the woman they'd freed from Koh's grip. She was wearing what looked like ancient Water Tribe clothes and was kissing a large man wearing similar archaic Waterbender garb. Korra smiled, realizing exactly who they were.

"Avatar Korra, I am Avatar Kuruk, the last Water Tribe Avatar before you," the man said. "I did much to fight the dark spirits as well, so I was proud to see you defeat Vaatu. But I never thought I would be reunited with my beloved Ummi."

"Koh had to die," Korra said. "Also, your wife was freed by Lord Vader, here." The past Avatar and his wife looked at the Sith Lord. While they were somewhat unnerved by his foreign power, they were genuinely grateful to Vader for having reunited them.

"Thank you for reuniting us, young Waterbender," Ummi said to Korra. "And by freeing me, you let me reconnect with my love. Kuruk has been brought back to you."

"And I have brought the others back to you," Kuruk said, to which many different figures of all four nations appeared behind him. Korra smiled, she'd restored her connection to the past Avatars. Then, she saw Avatar Kyoshi, who seemed almost angry at Korra, Avatar Roku, whose dismay with her was obvious, and the most recent past Avatar, Aang.

"It is a relief to know that there are now thousands of new Airbenders on our world, instead of a single handful," Aang said, smiling at Korra. "I am also proud to know you have befriended those from across the stars."

"Does that include me?" Vader intruded, looking at the ghost of the Avatar he had killed. Aang looked at his final adversary, trying to discern what was behind the mask, to no avail.

"Your Galactic Empire is a source of great concern, Darth Vader," Aang stated. "While your insides are so dark it's almost pitch black."

"That is ideal for opaqueness," Vader dismissed, before turning to Korra. "We've achieved our mission, it's time for us to return." Korra said it was good talking to the past Avatars, and followed her Sith master, having mixed feelings about having repaired her connection to them.

Kuvira is showing her appreciation for Suyin by trusting her with what began her journey to using the Force. I figured I would do opposing images of the Inquisitors, this chapter. Given what happened with Hama, I decided to address the Trope Being Tortured Makes You Evil, and how it can differ. I tried to recount Cal's adventures the way he would, BTW, in my version, Cal would have fought Imperial Army grunts on Bracca and Zeffo, and CSF on Coruscant.

I always figured that, even before she went to Republic City, Korra had her own personal goals, such as killing a famous monster like Koh. Given how Wan Shi Tong let Professor Zei starve to death despite being what the knowledge spirit wanted from his visitors, as well as how he sided with Unalaq and Vaatu, betraying Jinora to them, Korra would have zero problem killing him for getting in her way. The Imperials will copy everything in the library, using laser scanners for the books and such.

Having dealt with the Gods of Mortis, Vader knew how to overwhelm Koh with his own power. Koh knew nothing of Vader and wasn't cautious enough. Of course, Iroh I would show up, at some point, noticing how Vader's power is terrifying to all the spirits within the realm. As for the ghosts of the past Avatars, they aren't omnipotent, as shown by how Roku didn't know Aang was on a Lion Turtle. And being cut off from the current Avatar has only hampered their understanding. All they've received since Unalaq maimed Raava are glimpses of Elementia, while Korra was completely out of sight on another world. Given how Darth Vader is the most powerful and dangerous adversary an Avatar has ever fought, many of them don't like how Korra has befriended him.