Who are some characters that has ”unorthodox” force abilities?

The dark knowledge of the Sith teachings died with Kun, it is extremely unlikely that any records survive, either on Yavin IV or elsewhere.

Luke dropped his useless lightsaber and crouched. His every muscle suddenly coiled and tensed. He rallied all the powers of the Force around him, seeking any defensive tactic.

Luke called upon the powers that Yoda and Obi-Wan had taught him—but everything he did, every skillful technique, failed utterly. Against the full might of Kyp Durron and the forbidden weapons of the long-dead spirit of Exar Kun, even a Jedi Master such as Luke Skywalker could not prevail.

They had learned much of what Jacen had learned: skills that no other Jedi had known for centuries, if ever.

During Jacen's five-year journey, she had felt him growing steadily stronger in the Force-but also more distant and isolated, like a hermit retreating to his mountaintop. At times, he had seemed to vanish into the Force entirely, and at other times she had sworn he was floating just above her shoulder.

Luke is, perhaps, learning more about the Dark Side than he wants to know. The more the Emperor reveals, the more Luke is repulsed. The sheer depravity of the man would shake the soul of the strongest Jedi.

But Luke must continually remind himself of his vow to conquer the Dark Side from within.

Luke's father understood these secrets, these powers, and willingly used them to crush and enslave multitudes of Galactic citizens.

--

Satisfied that his "young apprentice" has crossed the threshold from which there is no returning, the Emperor unveils his teaching, and Luke is given the knowledge that was bestowed on his father before him!

Darth Bane's Rule of Two was a keystone of the Sith Order for centuries. The Battle of Ruusan, nearly a millennium ago, would have ended the Sith Order had Darth Bane not reconstituted it as a diarchy operating from the shadows. His writings became part of the Sith Archives passed down from master to apprentice for generations.

For a millennium, the Sith maintained the order in secrecy, passing down their evil heritage. As they gained knowledge of the dark side of the Force, their powers increased with each generation

The Sith had changed. The Sith had grown, had adapted, had invested a thousand years' intensive study into every aspect of not only the Force but Jedi lore itself, in preparation for exactly this day. The Sith had remade themselves.
They had become new.

Black armorweave and feats of strength weren't the only things that distinguished Darth Vader from Anakin Skywalker. Where Anakin had had limited access to the Jedi Temple data room, Vader–even light-years from Coruscant–could peruse any data he wished, including archival records, ancient texts, and holocrons fashioned by past Masters.

"Beyond this door lies the Holocron Vault. The Holocrons contain the most closely guarded secrets of the Jedi Order."

To Bane it seemed the teachings contained within the single Holocron surpassed those of the Academy's entire archives. Revan had discovered many of the rituals of the ancient Sith, and as the Holocron's avatar explained their nature and purpose, Bane could barely wrap his mind around their awesome potential. Some of the rituals were so terrible-so dangerous to attempt, even for a true Sith Master-that he doubted he would ever dare to use them. Yet he dutifully copied them down on sheaves of flimsi, preserving them so he could study them in greater depth later. And there was far more than just the ancient practices of dark side sorcerers stored inside the Holocron. In only a few short weeks he'd learned more about the true nature of the dark side than he had in all his time on Korriban. Revan had been a true Sith Lord, unlike the simpering Masters who bowed to Kaan and his Brotherhood. And soon all his knowledge-his understanding of the dark side-would belong to Bane.

For the next four days and nights he lost himself in the secrets of the ancient artifact. As he suspected, it had been created by Freedon Nadd. Bane delved into the Holocron's secrets with the aid of the gatekeeper: a miniature hologrammic projection of the long-dead Sith Master responsible for its creation. The gatekeeper guided and directed his studies, serving as a virtual mentor to those who sought out Nadd's lost secrets inside the sinister pyramid. Though Nadd had been human, his avatar was the image of a man who had succumbed to the physical corruption that sometimes affected those who delved too deeply into the power of the dark side. His skin was pallid, the flesh withered and sunken, and his eyes were glowing yellow orbs devoid of iris or pupil. Despite this, he still appeared as a formidable warrior: broad-shouldered, clad in heavy battle armor and the helm that had doubled as his crown when he had proclaimed himself king over the nearby world of Onderon.

…

But the orbalisk research was only the beginning. Freedon Nadd had been a Jedi who turned to the dark side as the apprentice of Naga Sadow, the former ruler of the ancient Sith Empire. Sadow's power had been so great, it had allowed him to survive for six centuries, fueled by the energies of the dark side. As his apprentice, Nadd had absorbed all his knowledge and teachings, transferring them into the Holocron before murdering Sadow and taking his place. Not surprisingly, most of the information inside the Holocron was hidden, locked away in the depths of its crystalline structure where it could be accessed only through time, meditation, and careful study. It would take many months, maybe even years, before Bane could lay claim to its greatest secrets.

BoD wrote:Not really sure how Caedus can claim no one has known those techniques before. Seems pretty self-aggrandising.

EmperorCaedus wrote:Exar Kun and Darth Caedus know some of the most unorthadox force abilities.

Kun's Sith Knowledge died with him:

The dark knowledge of the Sith teachings died with Kun, it is extremely unlikely that any records survive, either on Yavin IV or elsewhere.

Luke was completely defenseless to Kun's forbidden techniques:

Luke dropped his useless lightsaber and crouched. His every muscle suddenly coiled and tensed. He rallied all the powers of the Force around him, seeking any defensive tactic.

Luke called upon the powers that Yoda and Obi-Wan had taught him—but everything he did, every skillful technique, failed utterly. Against the full might of Kyp Durron and the forbidden weapons of the long-dead spirit of Exar Kun, even a Jedi Master such as Luke Skywalker could not prevail.

Also, Darth Caedus learned skills that no Jedi has ever learned, this includes Luke and Yoda: 

They had learned much of what Jacen had learned: skills that no other Jedi had known for centuries, if ever.

This can be explained by Jacen going on a 5-year journey, set on growing stronger in the force and discovering more esoteric abilities:

During Jacen's five-year journey, she had felt him growing steadily stronger in the Force-but also more distant and isolated, like a hermit retreating to his mountaintop. At times, he had seemed to vanish into the Force entirely, and at other times she had sworn he was floating just above her shoulder.

Luke had the knowledge of Vader:

Luke is, perhaps, learning more about the Dark Side than he wants to know. The more the Emperor reveals, the more Luke is repulsed. The sheer depravity of the man would shake the soul of the strongest Jedi.

But Luke must continually remind himself of his vow to conquer the Dark Side from within.

Luke's father understood these secrets, these powers, and willingly used them to crush and enslave multitudes of Galactic citizens.

--

Satisfied that his "young apprentice" has crossed the threshold from which there is no returning, the Emperor unveils his teaching, and Luke is given the knowledge that was bestowed on his father before him!

Vader's knowledge was also immense, it encompasses the Banite teachings, Jedi Temple vault, and the holocrons of Freedon Nadd and Darth Revan:

Darth Bane's Rule of Two was a keystone of the Sith Order for centuries. The Battle of Ruusan, nearly a millennium ago, would have ended the Sith Order had Darth Bane not reconstituted it as a diarchy operating from the shadows. His writings became part of the Sith Archives passed down from master to apprentice for generations.

For a millennium, the Sith maintained the order in secrecy, passing down their evil heritage. As they gained knowledge of the dark side of the Force, their powers increased with each generation

The Sith had changed. The Sith had grown, had adapted, had invested a thousand years' intensive study into every aspect of not only the Force but Jedi lore itself, in preparation for exactly this day. The Sith had remade themselves.
They had become new.

Black armorweave and feats of strength weren't the only things that distinguished Darth Vader from Anakin Skywalker. Where Anakin had had limited access to the Jedi Temple data room, Vader–even light-years from Coruscant–could peruse any data he wished, including archival records, ancient texts, and holocrons fashioned by past Masters.

"Beyond this door lies the Holocron Vault. The Holocrons contain the most closely guarded secrets of the Jedi Order."

To Bane it seemed the teachings contained within the single Holocron surpassed those of the Academy's entire archives. Revan had discovered many of the rituals of the ancient Sith, and as the Holocron's avatar explained their nature and purpose, Bane could barely wrap his mind around their awesome potential. Some of the rituals were so terrible-so dangerous to attempt, even for a true Sith Master-that he doubted he would ever dare to use them. Yet he dutifully copied them down on sheaves of flimsi, preserving them so he could study them in greater depth later. And there was far more than just the ancient practices of dark side sorcerers stored inside the Holocron. In only a few short weeks he'd learned more about the true nature of the dark side than he had in all his time on Korriban. Revan had been a true Sith Lord, unlike the simpering Masters who bowed to Kaan and his Brotherhood. And soon all his knowledge-his understanding of the dark side-would belong to Bane.

For the next four days and nights he lost himself in the secrets of the ancient artifact. As he suspected, it had been created by Freedon Nadd. Bane delved into the Holocron's secrets with the aid of the gatekeeper: a miniature hologrammic projection of the long-dead Sith Master responsible for its creation. The gatekeeper guided and directed his studies, serving as a virtual mentor to those who sought out Nadd's lost secrets inside the sinister pyramid. Though Nadd had been human, his avatar was the image of a man who had succumbed to the physical corruption that sometimes affected those who delved too deeply into the power of the dark side. His skin was pallid, the flesh withered and sunken, and his eyes were glowing yellow orbs devoid of iris or pupil. Despite this, he still appeared as a formidable warrior: broad-shouldered, clad in heavy battle armor and the helm that had doubled as his crown when he had proclaimed himself king over the nearby world of Onderon.

…

But the orbalisk research was only the beginning. Freedon Nadd had been a Jedi who turned to the dark side as the apprentice of Naga Sadow, the former ruler of the ancient Sith Empire. Sadow's power had been so great, it had allowed him to survive for six centuries, fueled by the energies of the dark side. As his apprentice, Nadd had absorbed all his knowledge and teachings, transferring them into the Holocron before murdering Sadow and taking his place. Not surprisingly, most of the information inside the Holocron was hidden, locked away in the depths of its crystalline structure where it could be accessed only through time, meditation, and careful study. It would take many months, maybe even years, before Bane could lay claim to its greatest secrets.

So, Luke Skywalker has immense cross-era knowledge that encompasses Banite teachings, the Jedi Temple vault, and so much more. But this knowledge was still much less than Darth Caedus, and completely defenseless to Exar Kun. With all of this, it is safe to say Exar Kun and Darth Caedus are the most knowledgeable characters, by extension learning some of the most unorthodox abilities in the mythos. 

> Korriban wrote:Vader has access to some things Luke definitely does not. Luke himself is a bit of a force virgin so attributing all of Vader's knowledge to him is quite funny. Vader knows about the creation of force storms and achieved a mastery of the Sith transfiguration techniques as of late 19bby at most a month after getting his suit. That alone is impressive. Naturally Vader would have access to Dooku's books and studies provided by Sidious which the count claimed "exposed him to powers beyond his wildest fantasies" additionally the banite archives and the Jedi temple's archives were at Vader's full access as well as knowledge from the blackguard. Being realistic everything the prophets of the Darkside know would be something Vader knows or has heard of. I'm DE Luke after being palpatines full apprentice remarks Vader "knows those dark books so well." Which again indicates his knowledge base. So banite lineage, Jedi temple archives, Blackguard and Inquisitorious as well as the teachings of Old Republic Sith like Darth Malgus. Yeah no wonder the guy was so powerful

> Korriban wrote:Vader has access to some things Luke definitely does not. Luke himself is a bit of a force virgin so attributing all of Vader's knowledge to him is quite funny. 

Excellent! Strike your brother -- then you'll see what new powers he's won from the Dark Side of the Force!

Being realistic everything the prophets of the Darkside know would be something Vader knows or has heard of. I'm DE Luke after being palpatines full apprentice remarks Vader "knows those dark books so well." Which again indicates his knowledge base. 

EmperorCaedus wrote:

> Korriban wrote:Vader has access to some things Luke definitely does not. Luke himself is a bit of a force virgin so attributing all of Vader's knowledge to him is quite funny. 

It seems to me as if you blatantly ignored the quote I provided, in which Luke is given the knowledge that was bestowed on his father before him. 

If that isn't enough, Sidious states that he has “won new powers from the Dark Side of the Force”, clear indications that he has taken up Sidious’ training in earnest, by extension proving he has the knowledge that was bestowed on his father before him:

Excellent! Strike your brother -- then you'll see what new powers he's won from the Dark Side of the Force!

Being realistic everything the prophets of the Darkside know would be something Vader knows or has heard of. I'm DE Luke after being palpatines full apprentice remarks Vader "knows those dark books so well." Which again indicates his knowledge base. 

You are doing an extreme amount of stretching for that quote to prove his knowledge is base, either way, the quotes I have provided above make it clear Luke knows the knowledge that Vader was bestowed upon, copious amounts of stretching isn't needed here.

@> Korriban

BoD wrote:Is there even any evidence that Luke kept learning dark side techniques after DE? Vader had around 2 decades to learn all of this. Luke had, what, a few months? Doesn't matter how good you are, you're highly unlikely to understand, recall and master centuries worth of knowledge in that time.