All these weaknesses also exist in the form of Vaapad. Juyo and Vaapad are pretty much the same. The only difference is that Vaapad is a Jedi variant. Jedi can use the Dark Force just like the Sith Lords in Juyo. Both variants have the same strengths and weaknesses. Like Juyo, Vaapad is an unpredictable form. Vaapad seems to have illegible attacks and incomprehensible emotional energy. Mace Windu was famous for his attack, known as the «flattened purple fireball.» It was his purple lightsaber, which came from all angles at lightning speed. Mace Windu derived this shape from Vaapad`s blade. While facing Darth Sidious in a duel in 19 BBY, the Sith Lord quickly brought down Mace Windu`s three Jedi companions. To combat Sidious` anger technique, Windu went entirely to Vaapad. It allowed him to fully channel his inner darkness and accept and use Sidious` darkness.
When he was completely immersed in his form, Windu`s combat power was such that he could allow his body to automatically fight for him without having to direct it with his mind. Sidious` own rage was used and redirected by Windu through the use of Vaapad, a process Windu mentally compared to a lightsaber deflecting a blaster bolt at its source. After Windu disarmed Sidious, the Sith Lord attempted to blow him up with the Lightning Force, but Windu responded by again using Vaapad techniques to channel the dark power of lightning through him without affecting him; Then he redirected it to its source. However, Windu thought that his use of Vaapad alone was not enough to defeat Sidious, as he thought it would only lead to a dead end.  Jedi Master Weequay Sora Bulq, already considered one of the Jedi Order`s top lightsaber practitioners and skilled in all seven forms, helped Mace Windu perfect Vaapad in the final years of the Republic. The Sith had no such inhibition, and Darth Sidious went so far as to call it the «Sith style.»  Form vii is known as Juyo, also known as the form of ferocity, or the path of Vornskr. The Jedi Order used Form VII in the early days of its founding. Later, they began to consider this form as a malignant form.
A variant of the VII form of the lightsaber appeared much later. One of the last Jedi Masters of the Old Republic, Mace Windu, created this form. He named him Vaapad, after a creature from the planet Sarapin. Let`s talk about both forms in detail. The only student Mace Windu ever taught at Vaapad was his Padawan, Depa Billaba. Under Windu`s leadership, Billaba became a master of the Vaapad, and Windu considered her virtually unbeatable in personal combat. During a mission with their master in Nar Shaddaa, Billaba and Windu were forced into a deadly confrontation with a mutant giant. They barely survived the encounter, and Windu later commented that Billaba had shown blade work that day that surpassed his. During a mission to Haruun Kal, Billaba fell to the dark side, allowing jungle blood fever and Vaapad`s attraction to take over. Mace Windu was forced to go to Haruun Kal and face his student in a duel. Windu discovered that the only way to survive against his former Padawan was to surrender to Vaapad entirely, but realized that he would also fall to the dark side if he did. Windu turned away from the dark side and gave up the fight, deliberately opening himself to Billaba`s fatal blow.
Billaba, seeing what had become of herself, tried to commit suicide, but was stopped by timely intervention from the outside.  According to Jedi Combat Master Cin Drallig, who served in the last days of the Old Republic, Form VII was so demanding that only Masters who could practice several other forms were able to use it effectively. Drallig explained that the mastery required to learn Form VII was such that only a privileged few were allowed to use it; He banned everyone from studying.