Later, Danny sells some of his dad's stuff, which was covered with Technus's ectoplasm. The gadgets collected and turned into a robotic armor that Technus uses. This is probably how he got back into the human world.
He is primary Ecto-Mechanical in nature, mainly linking himself to either a mechanized power armor or any other form of basic technology (such as turning himself into a Ecto-based computer virus, etc.).
Technus also is similar to other comic book villains such as Brainiac, Swayzak and Ultron in the sense for the first and third out of those characters that in nearly every new appearance on the show he is nearly always in some new upgraded Armor/Form, and the second out of those characters for being a computer virus.
Technus first appears in the episode "Attack of the Killer Garage Sale." Upon his first escape from the Fentons' Ghost Portal, he declares his name and purpose to Danny Fenton, who was in the lab at the time.
The ghost-boy inadvertently plants the idea for world domination in Technus' head, setting off his streak of villainy. Danny manages to apprehend him with the Fenton Ghost-Weasel, which promptly explodes, splattering Technus' ectoplasm across various devices in the lab.
The self-proclaimed "Ghost Master of Science and Electrical Technology" infuses his consciousness into these machines, sold by Danny at a garage sale. He manifests himself inside the computer of Dash Baxter, summoning the garage sale items to form a robotic battlesuit.
Virtually invulnerable to attack, Technus is defeated when Tucker Foley hacks into the shoddy software the ghost uses, shutting down his battlesuit and enabling Danny to apprehend Technus.
He later made a cameo (although, somehow in his battlesuit again) in "Prisoners of Love" where he, Skulker, the Lunch Lady Ghost, the Box Ghost, and Desiree were in Walker's prison and after some convincing from Danny Phantom, he and all the other prisoners worked together to get out of the ghost prison.
In "Teacher of the Year," Technus returns to get revenge but after seeing Danny play the video game, Doomed, Technus decides again to build a battlesuit based on Sam's character Chaos, but is thwarted by Danny and his friends. In response, he abandons the suit, planting himself inside the online computer game Doomed as a player.
After learning about the game's rules and objectives from Tucker (who believed he was helping out a new player), Technus goes on a race to beat the game and access the Internet, which will allow him to spread his consciousness. Tucker and Sam are unable to stop him, as the ghost can use his powers in the game.
Danny, able to do the same, uses this to his advantage; he and his friends imprison Technus through a glitch of the game dubbed "Level 0," a zone with only one way in and no way out.
He then appeared in "Reign Storm" as a cameo (this should have been impossible, as he was still trapped in Level 0). He still is in the battle suit he used in "Teacher of the Year."
In "Identity Crisis," Danny inadvertently deletes the game Technus is imprisoned in, freeing him into the computer's hard drive. He added a mustache and glasses to a photo of Paulina then Danny uses the Fenton Ghost Catcher to remove Technus from the computer.
He then uses a wireless connection to possess Tucker's PDA, and eventually to fuse with the Fenton RV, doing the same drawings to a photo of Jack, building another battlesuit from supplies in a department store.
With an upgraded personality that does not blurt out his evil plans, the ghost is re-dubbed Technus 2.0. Danny, separated into his ghost and human halves, is, at first, unable to stop Technus as he drains power from the city. Eventually, he possesses the mainframe computer of the Fenton's house, turning it into a walking fortress.
Danny Fenton and Danny Phantom work together to separate Technus from the house where he has gained a new look. He is then entrapped by the Fenton Thermos once more.
In an alternate future ("The Ultimate Enemy"), Technus used another one of his battlesuits to fuse with Skulker's to become Skulktech 9.9. Skulker composed the upper body while Technus ran as the operating system, but also composed the lower body, with his face on it.
Oddly enough, if one looks closely they can also see SkulkTech 9.9 aiding in the effort to make the earth intangible as well.
Technus also appeared in "The Fright Before Christmas" as one of the many ghosts who helped Danny save Christmas by putting his hand on a power transformer causing the town's Christmas lights come back on.
Technus appeared during "Secret Weapons," though only for a few (humorous) seconds in a bath towel and showering cap. It should be pointed out however, that he does tie in with the plot: Skulker steals his electro-staff while Technus was taking a shower.
The electro-staff was one of the items needed to upgrade Vlad's stolen Ecto-Skeleton (Vlad refers to the weapon as the "Lightning Rod"). Unfortunately, it blew up with the rest of the Ecto Skeleton.
"Flirting With Disaster" marks Technus's most recent appearance, in which he (now sporting a mullet) cracks a ten-thousand digit access code to gain access to a satellite orbiting the Earth.
He is able to keep both Danny and Valerie from catching up with him by manipulating them into a relationship, and possessing Valerie's ghost fighting suit.
Technus eventually breaks the code, and uploads himself to the satellite, spreading clones of himself and causing worldwide chaos. Danny manages to destroy the satellite after an extensive space battle, neutralizing the clones and stopping Technus' takeover.
Technus appears near the beginning and end of the series finale, "Phantom Planet." He's first seen reduced to petty theft, robbing an electronics store for DVDs and electronic equipment; Danny attempts to stop him and fails when Technus creates a new, remotely-controlled battle suit made of a taxi and computers.
Both Technus and his Car-Puter are stopped by Vlad's team of Ghost Catchers, the Masters' Blasters.
Technus appears in the episode's countdown as one of the many ghosts to assist Danny and Skulker by turning the entire planet intangible, so that an asteroid may pass through it. (If one has a keen eye, you can at one point see Technus 2.0 holding onto the tower directly beside Technus 1.0 in his battle armor from "Teacher of the Year.")
Technus has two different humanoid forms seen over the series. Technus 1.0 is a tall green-skinned ghost with white hair that's pointed upward. He has red eyes covered by rectangular black sunglasses and jagged teeth.
He wears a white collared shirt and black tie, a light blue-gray lab coat with a green belt, and green gloves. His coat tapers off into a wispy ghostly tail.
In "Identity Crisis," Technus upgrades into Technus 2.0, a taller and more well-fit version of himself with legs instead of a ghostly tail. He still has green skin and white hair, but his hair is now combed back into a mullet and his teeth are straight.
He now wears a long black coat with three green buttons and pockets, a black belt with a rectangular belt buckle, and a light blue-gray cape that covers his shoulders and is held closed at the neck. He also wears black boots and green gloves.
Although a genius in his own right, Technus is an incessant and overly egotistical braggart, originally with a tendency to shout out his plans to his enemies before he has a chance to finish them, often exposing himself and his flaws as a result.
He also has a penchant for using painfully outdated slang, such as "hip" and "far-out." Throughout the story he becomes more and more arrogant, and bent in upgrading himself into his most powerful self through any means necessary.
After his upgrade, Technus displays more of a villainous manner, becoming more heartless and showing tendencies of a sociopath similar to Vlad as well as showing a disregard for human life.
He also take pleasure in using human emotions to his advantage such as when he manipulates Danny's and Valerie's emotions such as their love and desire as well as her hatred for ghosts against them. Danny also states that he hates emotions.
Powers and Abilities
- Intangibility, Invisibility, Overshadowing, and Flight: Standard ghost power.
- Superhuman Strength: He is almost as strong as Danny. With a robot body, his strength level increases.
- Technopathy: Technus' main power is his ability to telepathically command and control machinery and computers. With this, he can animate electronic devices, convert harmless machines into weapons, or combine them into a larger form, usually a battlesuit.
- Machine Summoning/Apporting: He is able to conjure machines out of thin air.
- Machine Overshadowing: Technus has the unique ability to overshadow machines. Technus is also able to possess machinery, traveling through wiring and other channels between devices, as well as becoming part of a computer program like he did when he became part of a video game in "Teacher of the Year." He is also shown able to possess machines and give them great powers, as well as his own standard ghost powers.
- Upgrading Power: In "Identity Crisis," Danny inadvertently deletes the game where Technus is imprisoned in, freeing him into the computer's hard drive. Once he was in there, he started upgrading himself with the data he found to become "Technus 2.0," getting not only a new look but also greater powers.
- Upgrading: As he was able to upgrade his own body, Technus has demonstrated the ability to upgrade any form of technology as he did with Valerie's suit in order to keep Danny distracted. 
- Hardware Fusion: In "Flirting With Disaster," he can alter his physical composition into electrical wires and cords, as well as crack computer codes and transform himself into data.
- Lightning Rod Summoning: As seen in "Attack of the Killer Garage Sale" Technus is able to summon a lightning rod that is able generate electricity. Also, as seen in "Secret Weapons" it is seen being capable of projecting beams of electricity and can act as a power source of unlimited energy.
- Telekinesis: Visible in the form of green energy around the subject of the telekinesis. He can use his telekinesis to render his enemies immobile.
- Teleportation: Technus can teleport as well as physically move by transforming into a data-like form.
- Electrokinesis: In his upgraded form, Technus has demonstrated the ability to control electricity, absorbing it and wielding it at will. He also becomes stronger and faster, and his ghost rays change in color from green to blue. This power is seen in "Identity Crisis," "The Fright Before Christmas," and "Flirting With Disaster."
- Ghost Ray: He is also able to fire green and blue ghost rays. While in his battle suits he can also fire purple and blue blasts.
- Ghost Stinger: He uses his electric powers to electrocute Danny until he returns to human form.
- Electric Ghost Shield: He can create green ghost shields that resemble circuit boards, he can also use his shields to entrap things, and electrocute them.
- 104. "Attack of the Killer Garage Sale"
- 108. "Prisoners of Love" (no lines)
- 112. "Teacher of the Year"
- 204. "Reign Storm" (no lines)
- 206. "Identity Crisis"
- 208. "The Ultimate Enemy" (mentioned)
- 210. "The Fright Before Christmas" (no lines)
- 211. "Secret Weapons"
- 212. "Flirting With Disaster"
- Technus has some similarities to the Spider-Man villain Doctor Octopus. Both are obsessed with technology, and at some times, Technus uses mechanical attachments similar to Octopus's own mechanical arms.
- His full name is a reference to scientist Nikola Tesla.
- Technus is a playable character in SpongeBob SquarePants featuring Nicktoons: Globs of Doom. He has a laser blaster that takes up most of the lower part of his arm, and is dressed in his Technus 2.0 outfit.
- His voice resembles that of renowned voice actor Gilbert Gottfried, voice behind Iago from Disney's Aladdin and Digit from PBS Kids's Cyberchase
- Technus was originally going to be upgraded into Technus 3.0 in "Flirting With Disaster." The design for Technus 3.0 made it all the way through the board pitch for the episode, "Identity Crisis" but then it was realized that the design didn't work for what needed to happen in the story.
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