Obi-Wan Kenobi was highly skilled in Form III. Over the course of the Clone Wars, Kenobi continued to develop his skills.
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.
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.
Practitioners of Form IV included Yoda, Qui-Gon Jinn, Aayla Secura, Ezra Bridger, the Grand Inquisitor, and Anakin Skywalker.
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.
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.
Practitioners of Form V included Jedi Masters Aayla Secura, Adi Gallia, Plo Koon and Luke Skywalker, Jedi Knights Anakin Skywalker and Ulic Qel-Droma, and Dark Lord of the Sith Darth Bane.
In more recent years, the form was mastered by the Jedi swordmaster Cin Drallig along with the other six forms. Grand Master Yoda and Swordmaster Mace Windu were also proficient in its usage, as they were said to have fully mastered all the seven forms of lightsaber combat.
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.
A prime example is Kit Fisto. Kit Fisto was a Skilled Jedi of form I who fought during the clone wars. He almost defeated general Grievous using Form I of lightsaber combats. Other than Fisto, Meera Sutrik, and Obi-Wan Kenobi are the notable names to use Form I of lightsaber combats.
Billaba became Windu's Padawan and trained under the Jedi Master in the ways of the Force. During her training, Windu allowed her to study Form VII variant known as Vaapad. She eventually became a Jedi Knight, renowned for her skills with a lightsaber and favored Form III when teaching other Jedi.
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.
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.
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.
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.
You might not expect it from his calm demenour, but when you consider Qui-Gon's backstory, you'll understand his chosen form: that of Form IV, Ataru, or 'The Aggression Form'. Qui-gon is a rebel, constantly going against the wishes of the council in order to carve out his own path.
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.
However, Mace Windu—the legendary Jedi Master who popularized purple lightsabers—made modifications to Form VII that aligned it with Jedi philosophy and earned the endorsement of the Council. Windu's Jedi-approved variant of Form VII is known as Vaapad.
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.
Cin Drallig, Sora Bulq and Grand Master Yoda were also considered swordmasters. All three of them had mastered every known form of lightsaber combat and Sora was known for helping Mace Windu develop his Vaapad fighting style.
Shii-Cho, also known as Form I, is the oldest and most elementary form of lightsaber combat developed by the Jedi Order. Shii-Cho is still taught to youngling Jedis because it is the most basic. This style is known to be used when all other forms of combat have failed.
Though Qui-Gon was killed in a duel with a Sith Lord, his dying wish was granted, and Anakin became a Padawan learner apprenticed to Obi-Wan Kenobi. Over the next decade, Anakin's power continued to grow. Many Jedi wondered if he was the Chosen One destined to restore balance to the Force.
During the Jedi Civil Wars, some famous Jedi masters like Vrook Lamar, Zez-Kai Ell, and Kavar were proficient in form vii, Juyo. The Sith blade master Kas'im was an instructor at Sith academy before the “rule of two.” He was a skilled master of Juyo, and he taught many Sith lords how to use form vii.
Form IV, also known as Ataru, the Way of the Hawk-Bat, or The Aggression Form, was the fourth of the seven forms of lightsaber combat. The history of Ataru stretched back through the Old Republic, to at least as early as the Mandalorian Wars, where it was commonly employed by Jedi of that day.
His Padawan, Ahsoka Tano, was also known to favor Form V. Form V was a physically demanding style, calling on the user to quickly transition from a dedicated defensive stance to an all-out attack.