Form VII: Juyo/Vaapad
From the Encyclopedia of Speculative Fiction - http://encyclopedia.wizards.pro
Form VII: Juyo/Vaapad was the final form of the seven forms of lightsaber combat.
Dubbed the Way of the Vornskr, Juyo was considered an incomplete form for millennia. Undeveloped and rarely used, Juyo was not seen as one of the main forms until it was further developed by Jedi Master Mace Windu, who completed it with his Vaapad fighting style, thereby finally completing Form VII. (In 22 BBY, Palpatine noted that he had only ever heard of six forms; Mace's reply indicated that this had been the case - until he finessed Juyo into Vaapad). The most challenging and demanding of all forms, Form VII required intense focus, a high degree of skill, and mastery of other forms. Only four Jedi ever mastered Vaapad fully: Mace Windu, Depa Billaba, Echuu Shen-Jon, and Sora Bulq, who instructed Quinlan Vos in a few of its basics. Sora Bulq helped Windu develop Vaapad, but Bulq proved too weak to master the flow of the light and dark sides of the Force generated by the use of the technique, and fell to the dark side. Mace Windu noted that Vaapad mastered Bulq, not the other way around. Depa Billaba and Echuu-Shen Jon similarly fell to the dark side when combining Vaapad with the rigors of war. General Grievous used his technical prowess to copy Vaapad to a degree when he fought Mace Windu, though due to his lack of Force sensitivity, he could not truly master it.
Intrepid, somewhat direct movements were used in combination with advanced techniques involving Force-powered jumps and motions. Form VII did not appear as fancy as Form IV, as there were not moves like twirling and flipping, but the technical requirements were much higher. Vaapad used seemingly free-wheeling and open movements, but with utter control on the part of the wielder. In Windu's duel with Palpatine, Windu constantly had his arms spread wide, torso open to stabbing motions by Palpatine, as though Windu was daring him to strike. While appearing reckless on the surface, Windu knew exactly what he was doing. The end result, if practiced correctly, was a very unpredictable lightsaber style. The staccato swings and flow of the form made it seem as if the attacks were not linked - but in reality, it was merely confusing the opponent.
Form VII demanded the emotional and physical intensity of Form V, but it much more effectively controlled it (if mastered). Form VII, when fully mastered, resulted in extraordinary power.
However, Vaapad bordered on the edge of falling to the dark side, as it channelled one's anger and darkness into the attack. Only Windu's mastery and concentration on the light side prevented him from succumbing to his own anger, which is why Vaapad was rarely practiced and very dangerous. As noted above, the only other known practitioners of Vaapad, Sora Bulq and Depa Billaba, both fell to the dark side of the Force.
With that said, Vaapad was not just a fighting style. It was a state of mind and a power. The state of mind required that a user of Vaapad allow himself to enjoy the fight. He had to give himself over to the thrill of battle, the rush of winning. Vaapad was a path that led through the penumbra of the dark side. The power of Vaapad was simple: it was a channel for one's inner darkness; and it was a reflecting device. With strict control a person's own emotions and inner darkness could be changed into a weapon of the light.
Vaapad was also a superconducting loop, with the user on one end and the opponent on the other. Vaapad was able to take the powers of the opponent and reflect it back at them. 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. Also, when Palpatine unleashed his Force Lightning on Mace, he was able to use his lightsaber, with the power of Vaapad, to reflect the lightning back at Palpatine, thereby causing the disfigurements to his face. Ironically, Palpatine was also probably well-versed in Vaapad (or at least his own version of it), since he used the reflected lightning and his own pain to fuel his continuing attacks, which only served to disfigure him more. It is interesting to note that if Windu had not used Vaapad on Palpatine, then he probably would not have lasted much longer than Masters Saesee Tiin, Agen Kolar, and Kit Fisto. This also explains why Windu wanted to kill Palpatine rather than let him stand trial, so immersed in Vaapad's power as he was. Being a dark side user, Palpatine was probably accutely aware of this and used Vaapad's drawbacks to defeat Vaapad's creator (goading Mace into attempting to "assassinate" Palpatine, thereby becoming the catalyst for Anakin Skywalker's fall to the dark side).
Nevertheless, the power of Vaapad was quite incredible. It was at once a form of lightsaber combat, a state of mind, and an actual tangible power. To use it required great mastery, discipline and, above all else, purity of heart and spirit. Vaapad users were intense, focused and introverted. There were even signs of pent-up hostility in them. Mace Windu was the obvious caricature of a Vaapad user, and so he must be used as the litmus test.
New information suggests that Mace Windu's creation of Vaapad was less a true "creation" of a form, and more a refinement. However, because of Juyo's difficulty, it remained largely unused.
Around the time of the Jedi Civil War, Juyo was already the lightsaber form relied upon by the greatest of the Jedi, indicating that Juyo was indeed a complete and effective form for millennia before Mace Windu finessed it with Vaapad.
Furthermore, Darth Maul used his own deadly variant of Juyo coupled with his martial prowess to defeat several skilled Jedi, including Master Qui-Gon Jinn.
For more Information on lightsaber combat, and a list of Sources see lightsaber combat.