Form VII: Juyo / Vaapad
Form VII has been an oddity for millennia. It was modified by Jedi Master Mace Windu, who used it to create his Vaapad fighting style. The most challenging and demanding of all forms, Form VII requires intense focus, high levels of skill, and mastery of other forms. Form VII is without question the rarest form, and only two Jedi have ever mastered Vaapad fully: Mace Windu and Depa Billaba. Sora Bulq, who instructed Quinlan Vos in a few of its basics, never fully mastered Vaapad, Mace Windu stated that Sora knew "almost as much as him". As stated in Star Wars Insider, Darth Maul was trained in Form VII combat as well. Sora Bulq helped Windu develop Vaapad, but Bulq and Mace's Padawan, Billaba, proved too weak to master the flow of the light and dark sides, and fell to the dark side. In this way, Vaapad mastered them. Many believed Plo Koon could master Form VII, but he believed that it was too dangerous so he took on Form V instead. In KOTOR II, the Jedi Exile can learn Juyo from Master Kavar, but only if the Exile is a Guardian, Weapon Master, or Marauder.
Sometimes used as another name for Form VII itself, Vaapad is in fact a "sub-form" of Juyo. The term Vaapad comes from a non-sentient predator on the planet Sarapin and its moons. A Vaapad has no fewer than seven tentacles, while the largest ever killed had twenty-three. However, the tentacles moved so extremely fast that no one could actually count the tentacles until the monstrosity was slain. Standard Juyo contains sleek, fast movements with strong strikes, whereas Mace Windu's specialized Vaapad focuses the use of the Force and emotion to fuel attacks (which explains why Sora and Depa both fell to the dark side in using it) normally used in Juyo. Regular Juyo can be mastered (or at least "sub-mastered") much more easily than Vaapad, but Juyo can never truly be used to its full extent unless training in Vaapad is taken. Standard Juyo is not as powerful as Vaapad, but lessens the risk of falling to the dark side.
Intrepid, somewhat direct movements are used in combination with very advanced techniques involving Force-powered jumps and motions. Form VII does not appear as fancy as Form IV, but the technical details of it use very open movements resulting in a very unpredictable battle style. The staccato swings and flow of the form make it seem as if the attacks are not linked—but in reality, it is merely confusing the opponent. This style is very similar to the martial art of ninjitsu. The sword techniques of this art are very practical, using "battlefield" philosophy; kill, move on.
Form VII demands the emotional and physical intensity of Form V, but it much more effectively controls it (if mastered). Form VII, when fully mastered, results in extraordinary power.
Only through the learning of several other forms could a Jedi began to understand Form VII, being the most demanding combat style. It involved so much physical combat ability that its training brings a Jedi very close to the Dark Side of the Force. To master Form VII, a Jedi had to employ bold movements and be more kinetic than in any other form. Form VII employed the use of overwhelming power directed through unconnected, staccato movements that kept an opponent continually off-guard.
However, Vaapad borders on the edge of using the dark side, as it channels one's anger and darkness into the attack—it may be related to Japanese shinkengata. Only Windu's mastery and concentration of the light side prevents him from succumbing, which is why Vaapad is rarely practiced and very dangerous. As mentioned above, the only two other known practitioners of Vaapad, Sora Bulq and Depa Billaba, both fell to the dark side of the Force.
Vaapad is not just a fighting style. It is a state of mind and a power. The state of mind requires that a user of Vaapad allow himself to enjoy the fight. He must give himself over to the thrill of battle, the rush of winning. Vaapad is a path that leads through the penumbra of the dark side.
The power of Vaapad is simple: it is a channel for one's inner darkness; and it is a reflecting device. With strict control, a person's own emotions and inner darkness can be changed into a weapon of the light. Vaapad is also a superconducting loop, with the user on one end and the opponent on the other. Vaapad is able to take the hatred, anger and rage of the opponent and reflect it back at him. In his fight with Palpatine, Mace Windu used Palpatine's own speed and hatred against him, reflecting it back against the Sith Lord and using it as his own power. Vaapad is at once a form of lightsaber combat, a state of mind, and an actual tangible power. To use it requires great mastery, discipline and, above all else, purity of heart and spirit. Vaapad users are intense, focused, and introverted; there are even signs of pent-up hostility in them.
In KOTOR 2, which takes place about 4,000 years before the Clone Wars, Juyo was one of the lightsaber forms that could be used, showing that even though Juyo was incomplete, it was still an effective form for millennia before Mace Windu completed it with Vaapad.
Darth Maul had mainly studied Form VII Juyo first, then enhanced it with his own hatred and anger as well as his own knowledge of martial prowess and a Sith lightsaber/double-bladed lightsaber. It is similar to Mace Windu's Vaapad where he channels his anger into attacking and giving himself to the thrill of winning a battle as described in the novelization of Revenge of the Sith.
In the novel Star Wars: Shatterpoint, Mace Windu indicated that part of Depa Billaba's Vaapad blade work has even surpassed Mace Windu himself and the Vaapad he created and used.
Another variation of Juyo is used by Master Cin Drallig in the Revenge of the Sith Video Game, whose personal style takes the extremely high speed at which Juyo operates and takes it to a Vaapad-like level without losing the power of normal Juyo (if the word 'normal' could ever accurately describe Juyo).
Vapaad gives the user a unique position for fighting dark side users, for when mastered, it allows the user to draw upon the dark side's strength. In Revenge of the Sith, Mace Windu might have been unable to defeat Sidious had it not been for his mastery of Vaapad.
Known practitioners of Form VII: Mace Windu, Sora Bulq, Depa Billaba, Quinlan Vos (Incomplete Training), Darth Maul, Cin Drallig, Master Kavar.