Obi-Wan Kenobi was highly skilled in Form III. Over the course of the Clone Wars, Kenobi continued to develop his skills.
Throughout his career as a Jedi knight, Obi-Wan used Form III Soresu in lightsaber combat, which was originally created as a counter to the dueling intricacies of Form II's fencing style and focused on minimizing movements while optimizing defense.
He has used multiple Forms to improve his prowess as a duelist since the start of the Prequel Series. By the time of RotS, Obi-Wan exercised Forms 1, 3, 4, 5 (Shien) & 6 in battle, Soresu and Ataru being his main focus in their stated order.
Obi-Wan originally used Form IV commonly known as Ataru like his master, Qui-Gon Jinn. After Qui-Gon's death, Obi-Wan realized the flaws of Form IV and instead became a practitioner of Form III, Soresu, which is the most defensive of the seven lightsaber forms.
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 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.
Form VIII: Kendosu, or the Way of the Varactyl, was a new swordplay style developed during the Great Galactic War by Jedi Knight Scott Borek.
Qui-Gon Jinn and Obi-Wan Kenobi utilize Ataru against Darth Maul's Juyo on Naboo. Because it was such an aggressive style, Ataru was not generally optimal for use against multiple opponents, and it was somewhat ineffective against blaster fire, particularly from multiple foes.
Kylo Ren's lightsaber form was something of a hybrid, which blended three styles together: Djem So, Juyo, and Niman.
Yoda employs Form IV, which is called Ataru. As seen in his battles throughout the prequels, this particular form relies heavily on aggressive attacks and acrobatics, as well as an emphasis on using the Force to enhance their movements, strikes, and agility.
To the Jedi of the Clone Wars era, the most prominent practitioner of Form V was Anakin Skywalker, who mastered both Form V variants.
Obi-Wan could be aromantic and experience sexual attraction to others, or he could be asexual and experience romantic attraction. Either way, that's still a-spec. If the only person he is ever attracted to is Satine, there is a place on the aromantic and asexual spectrums for that.
Form V, also known by its two primary disciplines of Shien and Djem So, as well as The Way of the Krayt Dragon or The Perseverance Form, was the fifth of seven forms recognized as canon by the last Jedi Council for lightsaber combat.
Obi-Wan Kenobi was highly skilled in Form III. Over the course of the Clone Wars, Kenobi continued to develop his skills.
They typically taught the form to Jedi Sentinels. During the New Sith Wars, Niman was practiced amongst both the Jedi and the Sith forces. A notable Jedi adherent was Johun Othone, who took full advantage of Form VI's inherent versatility during the pitched battles of the war.
Practitioners of Form IV included Yoda, Qui-Gon Jinn, Aayla Secura, Ezra Bridger, the Grand Inquisitor, and Anakin Skywalker.
Rey's lightsaber was a yellow-bladed lightsaber that was constructed by the Jedi Rey Skywalker following the First Order-Resistance War.
Princess Leia Organa's preferred form is never specified, but her training in both continuities indicates that she also prefers Form V. Form V, with its two sub-disciplines of Shien and Djem So, is a fast and aggressive lightsaber form, focusing on overwhelming and overpowering opponents.
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).
Kylo Ren's Lightsaber Form
The evidence isn't entirely clear, but it is most likely that he was an adherent of Form V, particularly the Djem So variant. Ren's fierce fighting style has the hallmarks of Djem So, which demands a high degree of speed and strength to execute a flurry of attacks and counterattacks.
For much of the Clone Wars, Anakin used Form V in battle. Darth Vader also used lightsaber Form V, and the idea behind this technique was to end a fight before it could be allowed to begin. It was a heavy-handed style and executed with aggressive, powerful strikes.
Form II relied on careful and controlled strikes instead of power and strength. Count Dooku was a master of this form and trained the Sith assassin Asajj Ventress in its use, though hers was less elegant than her master's. The Grand Inquisitor was a proficient Form II practitioner.
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.
There are 7 forms of lightsaber combat, but Soreso, Shein, and Vaapad are the most effective. Soreso, Vaapad, Shein, are the most effective forms because they are all strategic and have their strengths and weaknesses. But the thing they all have in is that you must fully commit to the form.
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.