Dark Danny

"Your time is up Danny. It's been up for 10 years."

- Dark Danny to Danny Phantom.

Dark Danny, also known as Dan Phantom, and the evil older version of Danny Phantom and the main antagonist of Danny Phantom: The Ultimate Enemy. He was created as a result of the ghost forms of Danny Phantom and Vlad Plasmius fusing together. He is the most evil and one of the most powerful Danny Phantom villains.

He was voiced by Eric Roberts, who also played The Master in the Doctor Who movie, Sal Maroni in The Dark Knight, and James Munroe in The Expendables.

Creation
After Danny Fenton used his powers to cheat on the Career Aptitude Test in an alternate timeline, Danny's teacher, Mr. Lancer who'd been suspicious of him, asked his family to come to the Nasty Burger for a meeting. Sam and Tucker were also there, but the Nasty Burger's vat of condiments exploded, killing everyone except Danny.

Left orphaned by the tragedy, Danny was forced to move in with Vlad Masters, since no one else could understand his situation and despite the hatred that the two had shared for each other prior, Vlad treated Danny with great sympathy. However Danny couldn't deal with the guilt anymore and asked his former archenemy to remove his ghost half, believing that it was responsible for the deaths of his family and friends. He also thought that his ghost half would be free of all emotion, ridding him of the pain and guilt that he was feeling.

Vlad agreed to help and tore Danny Phantom out of Danny Fenton with the Ghost Gauntlets, but after the procedure, Danny Phantom did the same to Vlad and bonded with his ghost half, resulting in the two selves fusing together. As such, Vlad's evil overwhelmed and destroyed all the goodness of Danny's original ghost self and as such, Dark Danny was born. Now, no longer possessing any empathy or remorse, Dark Danny responded by brutally killing his former human self before blowing up Vlad's mansion. With that mission complete, Dark Danny then flew off to unleash a ten year period of destruction throughout the Human and Ghost Worlds.

Facing Danny Phantom
When the Observants saw the terrible future that Dark Danny had unleashed, they commanded Clockwork to destroy Danny in the past so as to prevent Dark Danny from ever coming into being. However the time ghost instead sent in various future ghosts that set off a series of events that caused Danny to end up in the future to confront Dark Danny, who'd been reducing the future Amity Park to rubble, having finally gotten through its ghost shield with his Ghostly Wail power. Danny was no match for his evil older self and eventually Dark Danny fused him with a time medallion that trapped him in the future so that the half-ghost wouldn't be able to stop him from coming into being.

Realizing that Clockwork was trying to stop Danny from turning into him, he threw his past self into the Ghost Zone to make sure he stayed out of the way and then transformed himself into a fourteen year old version of his human self. Dark Danny used another time medallion to go to the past to ensure the events that created him would happen, however Danny's sister, Jazz, found out what he really was.

He successfully cheated on the C.A.T. using the answers (which Danny had obtained earlier by accident), causing Lancer to call his parents over to the Nasty Burger as a demonstration of what awaited those who failed the test.

Sam and Tucker came to try and warn them of the imminent explosion and Jazz arrived, proceeding to use the Fenton Ghost Peeler to reveal Dark Danny. He managed to used ectoplasm to trap them on the condiment vat,which was coming close to exploding, but then Danny Phantom arrived, having succeeded in getting the time medallion out of him with help from the future version of Vlad.

Final Battle
Dark Danny could not kill his younger self, but only had to hold him off until the sauce exploded and even with the Specter Deflector and Ghost Gauntlets, Danny couldn't defeat his evil older self. However his determination to save his family and friends caused Danny to unleash the Ghostly Wail power, which he had used earlier while under attack by future versions of ghosts he had fought. This shocked Dark Danny, since he was not supposed to gain that power for 10 years and Danny told him that the future apparently was never as predetermined as he'd thought. He unleashed a second Ghostly Wail that blasted Dark Danny into a building, who emerged extremely battered and weakened and was trapped in the Fenton Thermos. However Danny was too weak to save his family and friends in time, but Clockwork's intervention saved them and he sent the half-ghost back to before the test so as to give him a chance to change his future. The time ghost then took charge of Dark Danny, who existed outside of the time stream now that Danny would never become him. However he was seen smashing against the sides of thermos, apparently attempting to escape.

Personality
Dark Danny is completely heartless and utterly callous, and while the other Danny Phantom villains had some level of morality, he has nothing of the sort, making him the most evil villain in the show. He is brutal, sadistic, destructive, ruthless, misanthropic, vicious, and remorseless, as well as being perfectly willing to kill anyone, even if they were people his human self cared about, in order to fulfill his own goals.

Dark Danny is also highly prideful, arrogant, and egocentric, most likely because there was no one in the future able to fight him, and this made him underestimate his younger self; as such, it is his arrogance proved to his major weakness, as it led to his defeat by his younger self. He proved just as inhumane and merciless to even his fellow ghosts, as he injured, scarred, or otherwise deeply embittered many of the villains in the series in his realm.

For all his pride and arrogance, he is also very intelligent, manipulative, and persuasive, as he was able to fool his younger version's friends in his world into thinking he is the one true Danny, at least for a brief time until he revealed his true colors. He is also shown to have a rather warped and sadistic sense of humor, as he quipped to his younger self's parents, "Hello? Danny Fenton? Danny Phantom? Ever notice the similarity?", though this could have been to sadistically taunt at his parents rather than make a joke.

He is also capable of fear, as he was stunned to see his counterpart developed the ghostly wail, a power that he wouldn't develop for a decade and was seen worried when Danny used it on him a second time.

Powers and Abilities
Dark Danny has the combined powers of Danny Phantom and Vlad Plasmius at his command, making him extremely powerful. Similar to his good counterpart, he can sense nearby ghosts and half-ghosts with red wisps of mist emerging from his nose when one is nearby. Dark Danny's ghost powers grant him superhuman strength, speed, agility, and durability and he can fly and turn invisible and intangible.

His most powerful attack is his Ghostly Wail, a powerful shriek of sonic force that sounds like moaning ghosts and can use it more than once without losing energy, unlike Danny who can only use it one or two times before feeling a severe energy drain. Dark Danny has a wide variety of powers and can possess other people, fire ectoplasmic energy blasts, unleash a pseudo-electrical attack to shock people, generate an ectoplasmic energy shield, create duplicates of himself, form bonds made of ectoplasm, teleport, shape-shift into a version of his younger self, create portals to the Ghost Zone, manipulate the shape of his body, use a sleep beam to knock people out, turn into ghostly vapor, and fuse objects into beings with his intangibility powers, making it unreachable by human or ghost means.

Quotes
"I'm still here! I still exist! That means you still turn into me!"

- Dark Danny while fighting his counterpart.

"Hello, Valerie. And goodbye."

- Dark Danny's attempt to kill Valerie.

"Strange how one massive fireball of highly combustible condiments can ruin your whole future."

- Dark Danny mocking the deaths of Danny's loved ones.

"...Actually, that was me. And you. Eventually."

- Dark Danny meeting his past self.

"Me, my future - I'm inevitable."

- Dark Danny.

"How? Is the answer A, the Fenton Portal? Destroyed it. B, the only remaining portal? The one my idiot cheesehead archenemy has? As soon as I find it, that's going too. Is it C, you? No. You can't stop me from cheating on the C.A.T. and solidifying my future, so it must be D--None of the above! Well, what do you know! The answer to the first question is D."

- Dark Danny declaration that no one will rescue Danny from the Ghost Zone or stop him.

"What kind of parents are you anyway? The world's leading ghost experts, and you couldn't figure out your own son was half ghost!"

- Dark Danny to Danny's parents.

"Hello? Danny Fenton? Danny Phantom? Ever notice the similarity? Jazz did."

- Dark Danny mocking Danny's parents.

"Actually, nobody's going anywhere. Not until it's time for you to be blown everywhere."

- Dark Danny to Danny's loved ones.

"I don't have to waste you. I just have to run out the clock until your entire life falls apart."

- Dark Danny to Danny.

"Sam and Tucker. It's been awhile. 10 years to be accurate. So, to what do I owe this little blast from the past?"

- Dark Danny seeing Sam and Tucker again after 10 years.

"You know, if I had an ounce of humanity left in me, this would be a very touching little reunion. But of course I surrendered my human half, a long time ago."

- Dark Danny to his former friends.

"Clockwork... meddling again."

- Dark Danny about Clockwork.

"Too weak to escape -- and you're too late to save them!"

- Dark Danny's last words.

Trivia

 * It was stated that if the series had not been cancelled and Clockwork's voice actor, David Carradine, hadn't passed away, Dark Danny would have indeed returned.
 * His younger self Danny first turned to the dark side in control freaks.
 * Dark Danny alongside Pariah Dark are the two most powerful and most evil villains in Danny Phantom. However, Dark Danny is considered more evil due to him wanting to destroy the world while the Ghost King wanted to simply rule it. On the other hand Pariah is considered more powerful due to him possessing the both the Ring of Rage and the Crown of Fire.
 * Due to him now existing outside of time and Danny changing the future, there is nothing preventing him from trying to eliminate Danny since they no longer have a life link.