Darth Ferb

"The Dark Side is my home now."

- Darth Ferb refusing to go with Phineas "If you will not join me, then I must destroy you."

- Darth Ferb after Phineas refusing to join the Dark Side of the Force Darth Ferb is Ferb Fletcher's Sith form, as well as the secondary antagonist of the Phineas & Ferb: Star Wars special. He didn't start off as a Sith, as he was helping his stepbrother give Obi-Wan the plans to destroy the Death Star, until he was accidentally hit by Darthenshmirtz's Sith-Inator.

Becoming Darth Ferb
While Phineas, Ferb and Isabella were in the Death Star, Ferb sensed that Perry the Rebelpus was in danger. So he decided to split up with Phineas and Isabella to rescue him. He followed his instinct all the way to Darthenshmirtz's lair. Just when Darthenshmirtz was about to fire his Sith-Inator towards Perry, who was frozen in carbonite, Ferb jumps in front of Perry, resulting in him getting shot by the beam. This resulted in him turning into a Sith simply known as Darth Ferb, which was seen by his orange sith-like eyes.

Confronting Phineas
When Phineas went on a search for his brother, he eventually ended up in Darthenshmirtz's lair, where Ferb was. Phineas notice that Ferb was a bit different as his skin turned red, black marking appeared all over his face, his green hair became almost spike-like, and his robe was black. Darth Ferb then introduces the Sith-Inator to Phineas, stating that he has upgraded it to create himself a new army of Sith warriors. Darth Ferb demands Phineas to join him in the Dark Side. At first Phineas scoffs at this like it was a joke, but upon seeing Darth Ferb threatening him with his lightsaber, Phineas realizes that Darth Ferb has gone out of control. The two fought each other in a Lightsaber duel, as well as constantly upgrading their Lightsabers. During the fight Darth Ferb managed to destroy Phineas' Lightsaber. Darth Ferb tried to convince to Phineas to join the dark side, but Phineas denied the offer.

Phineas tried to get Ferb to become good again. But instead, Darth Ferb was planning on using the Sith-Inator to turn Phineas into a Sith as well. Just when he was about to do so, stormtrooper Candace showed up to save Phineas, being mercy for saving her life. Phineas attempts to reach the inator, but Darth Ferb stops him from doing so. Candace tried to distract Ferb as Phineas was attempting to destroy the Sith-Inator. Phineas tossed his damaged Lightsaber into the self-destruct import, which caused the Sith-Inator to explode. After the Sith-Inator was destroyed, Darth Ferb reverted back to his good self.

Powers and skills
Darth Ferb appeared to be one of the strongest Phineas and Ferb villains. He is wielding a lightsaber and can use it far better than his brother Phineas, being able to active using of two lightsabers in the same time. He also a grand force user, being able to throw Perry though there was a big distance between them, also he crushed Phineas's lightsaber with force. He also seen as a great engineer, as he modified his lightsaber and Darthenshmirtz 's Sith-inator, both led to magnifically changes.

Trivia

 * Darth Ferb is a parody of Darth Maul.
 * Darth Ferb and his good side talk more than the original counterpart.
 * With his actions and absolutely non-comical appearance, Darth Ferb can be counted as one of the darkest and the most serious villains in the "Phineas and Ferb" fandom. (Need to know, even 2nd Dimension Doofenshmirtz, 2nd Dimension Charlene, Liam McCracken, Aloyse Von Roddenstein, and Smile Away Reformatory School Sergeant had some comical action in their roles).
 * Darth Ferb also is the first evil variant of alternative dimension Ferb Fletcher.
 * Darth Ferb is the only non-singing main villain in Phineas and Ferb: Star Wars Special. Also, he is a rare of Phineas and Ferb main villains who didn't sing at all, due to his serious appearance.