Gideon was the main antagonist of the sixth season of Charmed. What makes him different than most villains of the show was he was one of the Elders, who are a race of extremely powerful magical beings that are guardians of all good magic in the Charmed universe. He attempt to kill Piper Halliwell's son Wyatt Matthew Halliwell for "the greater good."
At an unspecified time, Gideon became the Headmaster of Magic School. It is possible he had been Headmaster since the school's creation after the destruction of Atlantis, as it was mentioned by the Elders that Gideon was the only one who could protect the school.
Gideon mentioned having met the first Charmed Ones when they were very young. After the Elders believed Leo killed Rennek, a powerful darklighter, he was the one who tells Leo about him becoming the whitelighter of the Charmed Ones in front of the Halliwell Manor.
He was also a supporter of the union of Leo and Piper in contrast to the rest of the Elders, and even went as far as to convince his fellow Elders to let them wed. However, after Wyatt Halliwell was born, Gideon grew concerned that the child was too powerful and became convinced that Wyatt needed to die to protect the Greater Good.
The Headless Horseman
In 2004, Gideon requires the sisters services when one of the students at Magic School conjures up The Headless Horseman and beheads people, including the sisters and Gideon's aide Sigmund. Gideon then panics when discovering that the horseman kills a mortal innocent with him realizing that he may have to shut the school down. When the student Zachary was discovered to be the one responsible for the horseman, he morphs into Paige to move the students away from Gideon before turning back into himself to attack him. After the sisters are returned to normal, they convince him to let Gideon go.
True Intentions Revealed
Some time later, Gideon hires a group of darklighters to kill Leo Wyatt, because he wasn't focusing fully on his elder duties. One of the darklighters, Damien, ended up being sucked into the Ghostly Plane with Piper and Leo. While in the plane, Piper and Leo reunite as a couple and make love, (conceiving Chris Halliwell in the process) before Damien impales Leo with an arrow. While this is happening, Gideon "helps" Phoebe and Paige with reversing a portal back to return the couple to the real world. Damien is killed by his leader upon returning. After the ordeal, Leo informs Gideon on the bridge that he can't justify staying on earth anymore, and stays in the heavens until Spin City, while Gideon goes to the Underworld to meet with the darklighter leader and reveal his true plan, which was to keep Leo away and distract the Charmed Ones while he kills Wyatt (who grows up to be evil and immensely powerful in an alternate future), whose birth he considers a mistake.
The Spider Demon
When Piper and her unborn baby are cocooned by the Spider Demon, the sisters call Leo back from the Heavens for help. He goes to Magic School for information on a wizard, which Gideon gladly provides before he growls at Leo for abandoning his Elder duties again. After the demon is vanquished, Piper agrees to stay at Magic School with Gideon for her safety, oblivious to what he is really up to.
The Tribunal and Barbas
When Darryl Morris ends up facing execution for killing a robber, due to the Cleaners removing exposure of magic the Charmed Ones used, Gideon gives them information on the Tribunal and then summons them. He acts as a lawyer for the sisters, while the Tribunal members summon Barbas. The Tribunal accelerates time while the case is proceeding to the point that Darryl is about to be executed while they read out their judgement. Barbas tries to convince the tribunal to relinquish the sisters' powers, but after finding out that Barbas deliberately carried out the plan by possessing a robber and Inspector Sheridan with phantasms, allowing him to be set free from purgatory. The sisters retain their ability to practice magic, but Phoebe loses her active powers. Barbas, technically the winner in the case, taunts Gideon by reading his greatest fear - that the sisters will discover his true intentions with Wyatt, but promises not to tell anyone.
In order to ward the sisters, Leo and Chris off Gideon's plan to kill Wyatt, he conspires with a demonic couple Corr and Clea to kill the sisters off in a demonic reality TV series. He does this by betraying a good witch, Tali, to her death by getting the sisters to protect her from the demonic contestants. Although one of his conditions was that no innocents were harmed, the demons, being evil, have other plans with a darklighter killing Tali and a shapeshifter stealing the appearance of the crime reporter Kyle to get to the sisters themselves. Gideon pretends to save the day by forging a page on magical projector crystals he bugged the Manor with. He then grabs a crystal to show a promotion for the series and claims that they're the ones after Wyatt. After the couple are vanquished, the sisters celebrate their success, with Gideon relieved that the sisters, Leo and Chris don't suspect him anymore. Sigmund, who knows of the plan all along, worries that their attempts to kill Wyatt would be the reason why Wyatt turns evil, but Gideon ends up vanquishing him before he confesses to the sisters.
The Parallel World
In his final attempt to kill Wyatt, Gideon was forced to contact his counterpart in the evil parallel world, so that world's Wyatt would be killed as well. To prevent Leo and Chris from intervening in their plan, both Gideons turn invisible and blocks the potion necessary to create a portal, thus injuring their hands. After the Gideons heal each other, they manipulate the portal plan so that the Chris's and Leo's would cross over into each other's worlds.
When the plan to return Chris goes horribly wrong for the good sisters, Paige and Phoebe are forced to track down their evil brother-in-law and nephew. However, evil Gideon sent their evil counterparts home, allowing them to move the good sisters through the portal and causing the worlds to turn unbalanced. The Gideons discuss this plan over a game of chess. Good Gideon sends Paige and Phoebe through the portal only to be attacked by the evil Gideon, telling them that they're not supposed to be there. The Pipers then lapse into labor and go to hospital - leaving good Gideon alone with good Wyatt.
His Intentions are Discovered
While Paige, Phoebe, Leo and Chris are in the evil world's underworld (which looks more like a flourishing garden) with the good Barbas, evil Phoebe and Paige arrive and attack their counterparts while Chris, Leo and Barbas take cover behind a large rock. When Leo wonders out loud about whether or not Gideon knew about the portal problems, Barbas suggests that Gideon know exactly how it could go wrong. Once the Pipers call the sisters to say that they are in labour, Leo and Chris inform them that they need to save Wyatt as well.
Meanwhile, the Gideons plan their attack on the Wyatts by orbing them out of their bedroom to the attic. They later bless an athame to penetrate his force field and kill him. Just then, the Wyatts orb the athame away from themselves and into the Gideon's chest before a power of four vanquishing spell is cast by the sisters. The Gideons orb back to the mirror to heal themselves, knowing that they can breach his shield and with the worlds now unbalanced, they try to use it to their advantage.
Working with Barbas
Gideon realised his mistake of causing a significant imbalance, but realised that Wyatt's death would be the "great evil" necessary to restore the balance between the two worlds. However, the sisters, Leo and Chris soon discovered that in Chris' timeline that Gideon took Wyatt away for several weeks in his attempt to kill the boy. While Wyatt was able to fend him off, the trauma of having to constantly defend himself as well as being betrayed by someone he thought he could trust was too much for his young psyche to handle, hence causing him to turn evil – thus making Gideon's concerns a self-fulfilling prophecy.
Meanwhile, the Phoebes and Paiges search in the Gideons' office when they notice an echo in the room. The Phoebes open the curtain masking the mirror after they notice a chess piece.
To help him make the necessary great evil, he enlists the help of Barbas, who sets to work scaring a cheerful Piper into bewitching her sisters to make them as unusually happy as her followed by torturing Leo with a hallucination of Wyatt growing up to be evil so that Wyatt's defenders would be distracted - allowing him to kidnap and kill Wyatt.
Killing Chris and Kidnapping Wyatt
Chris is looking after Wyatt and searching through the book, when he hears footsteps. He then tries to flee with Wyatt, but Gideon knocks him back. Gideon then conjures up his athame, which he then uses to stab and kill Chris, as he runs towards Wyatt's cot. Leo orbs back from the hospital after Barbas finishes taunting him with the possibility of losing two sons instead of just one, only to find out that Gideon has breached the force field, picked Wyatt up and orbed him to the underworld with Barbas, stating that "It's for the best, Leo.".
Once the pair return to the underworld, Gideon and Barbas argue over how to kill Wyatt, with Gideon preferring not to get stabbed this time round. After Gideon notes how apparently Wyatt is cocky by not having his shield up, Barbas grows tired, grabs the athame, and pounces on Wyatt himself - only to fall to the floor as Wyatt orbs away. This results in a chase around the underworld by the pair until Gideon, via voice manipulation, lures Wyatt into a crystal cage using his father's voice.
While Chris was dying, Leo had to go to Magic School. There he came face to face with his evil counterpart where they discuss how to save their sons. Evil Leo notes that he was full of hope while at the hospital, to which Good Leo responded with fear. Knowing that Barbas was responsible, they realize that in order to find Gideon, they need to find Barbas.
Upon trapping Wyatt, Gideon calls for Barbas to administer the killing - who apparently turns up to see him. "Barbas" criticises his lateness, to which Gideon snaps at his impatience. He hands "Barbas" the athame, who grows suspicious. Gideon asks if there is something wrong. "Barbas" states that there is - and proceeds to stab Gideon. "Barbas" transforms into Leo as he flings Gideon across the room. The real Barbas flames in and eavesdrops, while Gideon tries to defend his actions to kill Wyatt - including pulling the Elder card (to which Leo states that he is not one of them anymore) - but Leo refuses to have a bar of it.
After telling Gideon he was the reason why Wyatt turned evil in the first place, Leo orbs Gideon's magical mirror to the Underworld, and notifies Evil Leo on the other side not to kill Gideon. Gideon asks Leo what he was about to do. Leo replies with "A Great Evil," which was needed to restore balance to the parallel worlds. Leo strikes Gideon with lightning. Before Gideon dies, he curses Leo about the potential consequences of his decision before turning to dust. Leo destroys the mirror to prevent any future contact between the worlds, which had since been restored, due to a paragon of good being killed by another.
Aftermath and Legacy
After his death, the Charmed One's relationship with the Elders had become strained. They begun to question their motives. Leo would later on hunt down demons who would pose a threat to his son. He would even kill another Elder because Barbas exploited his fear and distrust of other Elders. Leo would even join the Avatars, an enemy of the Elders all resulted from Gideon's actions. The Avatars would ironically commit the very same crime that Gideon was guilty of; Committing acts of evil for "the greater good" which made the Charmed Ones turn away from the Avatars with the help of a demon master, Zankou. Eventually, the Charmed Ones and Leo would begin to trust the elders again.
Powers and Abilities
- Spell Casting: The ability to cast spells and perform rituals. Gideon used this ability to curse an athame.
- Apportation: The ability to teleport beings or items across different planes or dimensions, Gideon used this to summon a box of Ronyx Crystals and an athame.
- Conjuration: The ability to draw objects into existence. Gideon used this ability so create a door to Magic School.
- Divination: The ability to observe others through a Crystal Ball.
- Electrokinesis: The ability to manipulate electricity and fire bolts of lightning.
- Healing: The ability to heal the wounds of others, unless that being is already dead or evil.
- Invisibility: The ability to become unseen by the naked eye. His version was referred to as an "invisibility shield".
- Molecular Dispersion: The ability to utterly destroy objects and beings by tearing them apart on a molecular level.
- Orbing: The ability to teleport through the use of orbs. Gideon's orbs had a unique purple color.
- Portal Creation: The ability to open portals to other places and planes.
- Sensing: The ability to sense the location of other beings.
- Telekinesis: The ability to move objects and beings with the mind
- Telekinetic Orbing: The ability to transport objects with the mind through orbs. Gideon used this to orb Sigmund's head after he was decapitated.
- Transformation: The ability to change one object into another. Gideon used this ability to change the pages of a book into an entry on Ronyx Crystals.
- Reconstitution: The ability to reform the body after it has been destroyed.
- Immortality: The ability to possess an infinite lifespan and an arrested aging process.
- Gideon is the only main villain of the series who is not a demon (aside from Season 8's secondary antagonist Christy Jenkins).
- He is the first main villain to be vanquished in a season finale. The Source of All Evil and Cole Turner were killed around the middle of their seasons, and the Seer was destroyed in the second to last episode of Season 4.