Form IX: Kadeesh was a Form of lightsaber combat mainly focusing on the use of brute strength rather than Force-assisted movements or fancy and unpredictable parries.
Considered the most aggressive and unpredictable disciplines and therefore the most controversial, it was a combat style with a history of the Jedi High Council of the Jedi Order forbidding it and later allowing only select users to practice the disciplines.
Jedi Battlemaster Cin Drallig and Grand Master Yoda had knowledge and mastery of all seven forms, including Juyo, befitting Drallig's role as lightsaber combat instructor at the Jedi Temple and Yoda's reputation of having mastered all forms of lightsaber combat as did Anoon Bondara, another lightsaber instructor.
Form II, also known as Makashi (pronounced Muh-KAA-shye), was the second form of lightsaber combat invented by the Jedi Order. A somewhat aggressive, yet also graceful, combat style, it became a specialist form for duels with Sith opponents.
Kylo Ren's lightsaber form was something of a hybrid, which blended three styles together: Djem So, Juyo, and Niman. Djem So used an irregular reverse grip and was meant for practitioners who loved fighting with a more offensive edge - a perfect fit for Ren.
Qui-Gon Jinn was an Ataru master. The fourth lightsaber form, Ataru, originated some centuries after Form III. In many ways the inverse of Soresu, Form IV focused almost exclusively on offense. Its practitioners sought to end a fight as quickly as possible rather than outlast the foe.
A notable Jar'Kai master was the Priapulin Jedi Master Skwelli, who carried six lightsabers. He was renowned for his skill in his era, and recordings of his fighting form were considered a wonder to behold.
Darth Traya wielded three lightsabers telekinetically against her student on Malachor V. Kreia then returned to Malachor V, where she confronted Darth Sion and forced him to submit to her will.
In conclusion, Form VII, also known as Juyo or Vaapad, is undeniably the most aggressive lightsaber style in the galaxy. Jedi Master Mace Windu's mastery of this form exemplifies its power and its dangers.
As with his clone precursors, Starkiller was programmed with the knowledge and skills of his genetic template via memory flashes. As such, he inherited the original Starkiller's preference for the Form V/Shien-style reverse grip, as well as the Form IV/Ataru and Form VI/Niman fighting styles.
The black lightsaber, or Darksaber to give it its proper name, is one of the rarest lightsabers in Star Wars canon. Despite its rarity in canon, anyone who has seen the second season of The Mandalorian is likely to be familiar with the Darksaber.
Palpatine mastered all seven forms of lightsaber combat but preferred Form VII, Juyo. This seventh form was ideal for Sith Lords, utilizing their aggression for a ferocious form that favored offense.
At first, Rey primarily fights with a lightsaber the same way she would have with her quarterstaff. However, after studying Luke's Jedi scripture and training with Leia, Rey probably uses Form VI: Niman, a jack-of-all-trades lightsaber form that combines different aspects of Forms I through V.
Through the Force, Yoda was considered to have mastered Form IV to its highest level. He used it in almost all of his battles, and his mastery of the style caused others to describe him as virtually unstoppable against most opponents, including Separatist battle droids, despite his small size and advanced age.
The realistic answer seems to be, yes, Anakin in his prime could have defeated Luke Skywalker (in the current canon) if they battled one-on-one. The main reason behind this is Luke's lack of formal Jedi training, at least when it comes to combat.
Even though Kylo Ren uses a red lightsaber, harnesses the dark side of the Force, and wears a cape, he is not a Sith. Because of that, he can never hold the title of Darth. Instead, he was just a chaotic mess of the dark side (until he eventually found his way back to the light).
Luke acquired two notable lightsabers in the Star Wars movies, but the character used a third weapon in a recent comic. While the objects have been important aspects of the film series, the lightsabers have also been integral to canon materials.
The Clone Wars would later suggest that Grievous was denied the right to become a Jedi due to his lack of connection to the Force. Writers Dave Filoni and Henry Gilroy postulated that Grievous volunteered for cybernetic modifications to rival the Jedi that rejected him.
Darth Sidious, was in the earliest stages of his plan to take over the galaxy, and he was afraid a certain Jedi might get in his way. Interestingly, however, that Jedi wasn't Yoda or Master Windu, but instead Qui-Gon Jinn.
But while powerful, Dooku's saber form had one major flaw that would lead to his demise. The form Dooku mastered is Form II, also known as Makashi. It was one of the earliest forms established and even predates the creation of blasters.
Form VII, known by its two primary disciplines of Juyo and Vaapad; and also known as The Ferocity Form, was the seventh form of lightsaber combat. It was considered the most aggressive and unpredictable form.
