Obsessed

…

If you asked Sam, Tucker, and Jazz what Danny's ghostly obsession was before, they would have told you that he didn't.

…

As the electricity coursed through Danny Fenton's body, he could feel himself dying. At least Sam and Tucker are safe.

…

He glared at the ghost of the old lunch lady. How dare she threaten his friends! His school! His town! He would protect them, of that he was sure. He would protect them at all costs.

…

Even just looking at Vlad, a fellow halfa, filled him with rage. This was his town! Why did Plasmius think that he could just waltz in here and become leader of Amity Park?!

He needed to teach Vlad a lesson. The fruit loop would never return to his town.

…

"Psst, Danny, can I borrow a pencil? I can't do the test without one," Sam hissed. While normally Danny wouldn't hesitate to let Sam borrow a writing utensil, he get a strange surge of possessiveness.

It was a pencil!

But it was his pencil…

He shook his head. And despite his head screaming in protest, he handed one of his pencils over to Sam.

…

Gregor was bad news, Danny could just feel it.

He walked in, befriended Sam and Tucker within seconds, and had took some of Danny's Nasty Fries.

Well, now his powers had another use, keeping Tuck and Sam all to hi-

No. Making sure his friends didn't get hurt.

…

Gregor was kissing Sam.

Fury turned Danny's vision red.

Who did this guy think he was?!

He kissed Danny's friend.

Danny's.

And only Danny's.

And the foreign student would pay dearly for it later.

…

Sam frowned. Why did Danny always get mad at the people who were in a certain booth?

It was okay for him to have booth preferences, but he shouldn't act like somebody had stolen his property.

…

Danny shook.

Pariah Dark.

Had warped.

Danny's town.

Into the ghost zone.

Put it, and it's citizens.

In danger.

And was trying to claim it as his.

Well, the Ghost King needed to learn that it was Danny's territory.

And Danny's only.

…

Tucker booted up his computer. He and Sam were doing research.

They had both been concerned by Danny's behavior as of late. He was getting… selfish? No, that wasn't the word. Whenever somebody else came near his locker, he became snarky and aggressive. He had started beating up the ghosts more as more violently, more and more thoroughly.

He would always hiss something to them before capturing them.

The Box Ghost and the Lunch Lady had stopped showing up entirely.

Technus had seemed more cautious than usual.

So, Tucker and Sam were doing research on Ghost Obsession.

Ah, here was a good page:

Ghost Obsession: a ghost's goal in the afterlife. Often has to do with the last thought before death or goal in life. Examples of known ghosts below.

Ember McLain- being remembered. Having everyone know and remember her name.

Skulker- proving himself dominant via hunting of other ghosts.

Box Ghost- Boxes.

The Lunch Lady- making sure the lunch menu of Casper High stays the same as when she was alive.

Technus- electronics and world dominance.

The list continued on. This was a local Amity Park website, which would explain knowing the names of the ghosts. Finally, Tucker found what he was looking for.

Danny Phantom- still being studied by ectopsychologists. Obsession unknown.

Tucker frowned. Could half-ghosts have an obsession?

…

Mr. Gray was driving. Why? His brother, from the next town over, was visiting.

Luckily, he hadn't known of the latest development with Phantom, or his brother wouldn't have dared come close to Amity Park.

Mr. Gray would just have to pray that Phanton wouldn't notice.

Alas, it was in vain.

He glanced in his rear-view mirror, and saw Phantom in midair, holding his brother up and obviously threatening him.

When had Phantom gone so wrong?

…

"Listen, I don't know who you are-"

"M- my name's Edmund Gray."

"Okay then, Ed. This is my town. If you mess it up, I'm going to mess you up. Kapiche?"

Danny watched, satisfied, as the man bobbed his head up and down, terrified.

This was his town.

…

"Danny, I can hang out with other people!"

"Sam, you're my friend!"

"I can have other friends, too!"

"No!"

Tucker froze, as did Sam. What?

"You guys are mine!"

Sam slowly turned.

"No, we're not. We don't belong to anyone but ourselves!"

And Sam grabbed Tucker's arm and pulled him away.

…

Danny was fuming. They were his friends! HIS!

A breath of frosty air escaped his lips, and he saw the Box Ghost flying around. So the sucker decided to show his face again?

Bad move.

…

The Box Ghost laid broken on the ground. His eyes looked up pleading, but he found no mercy in the unearthly green eyes staring back at him.

Danny charged up one last blast of ectoplasm, and fired.

The Box Ghost gasped, and dissolved in goop.

The halfa smirked.

…

Skulker was flying towards his island. Hunting had been good that day.

As he glided by it, he considered going through the Fenton Portal.

No, he decided, I'm not in the mood to get my butt handed to me today.

And then he spotted something strange floating in midair.

A Fenton Thermos.

He examined it. Nope, no traps. But it did have a picture of the Box Ghost taped to it. Skulker removed the top.

A blob of ectoplasm came tumbling out, with a note that said:

I warned you

…

Despite herself, Sam was worried.

She was still angry at Danny, but he hadn't shown up for class today, and she knew for a fact that there were no ghosts currently. Less and less had been showing up.

Then, she spotted him flying above the school.

He was smirking at her.

…

Sam had seen Danny plenty of times since then, but all as Phantom. His parents were worried, skipping meals at times to look for him.

…

Jazz stared into her hot chocolate. Mom and Dad were out looking for Danny again. Why wouldn't he just come home?

The door opened. Jazz looked up, expecting two adults in jumpsuits, bit split into a huge grin when she saw it was her little brother. "Danny!"

"Hey Jazz." he said, like he did every day.

"Don't 'hey Jazz' me! You don't come home for days and freak out our parents, and me, and just go, 'hey Jazz'. I thought something was seriously wrong!"

He just shrugged. "I'm going to my room."

When she started to follow him, he glared at her with such an intensity, eyes glowing, that she took a step back.

He disappeared.

…

The Guys in White looked around, ready to examine Amity Park for any… problems.

It was to their surprise, however, when an ectoblast took out one of their own.

They looked around for the source, and their invisibility detectors sensed a ghost right above their heads, in the shape of the ghost boy.

They fired all of their guns at him, rapid, but all of them missed.

And soon, the last one's vision was enveloped by black.

They woke up in the middle of the desert, for the ones that did wake up.

…

Sam shivered. Danny hadn't shown up as Fenton for weeks. She wasn't sure if she did want to be around him.

And, in the middle of English, her phone rang.

Only emergency calls were able to get through currently.

She grabbed her cell and ran out of the classroom.

It was Jazz. "Sam…" she was sobbing.

"Jazz, what is it?"

"You better come here."

And there was a click on the other end.

…

Jack and Maddie were still staring in shock by the time Sam and Tucker got there.

The bed was rumpled and tussled. Maddie was holding a note.

Daniel is gone~

Find him if you can~

And on the back, it read:

Happy now, Sam?

Sam felt rage bubble up in her.

…

"Why did you do that?!"

Danny glanced nonchalantly at the goth. "Being a ghost is better for me."

"Why?" She demanded.

"I can protect my stuff better."

"The whole of Amity Park is not 'your stuff'!"

"Well, it's my territory, then. And I can protect my territory."

Sam's eyes pricked. "What happened to you…?"

And she ran off.

…

Tucker was looking at that ghost obsession website. It had been updated.

Danny Phantom- Possessive/Territorial

Tucker sighed, melancholy.

…

Now, if you asked Sam, Tucker, and Jazz what Danny's ghostly obsession is, they would just look at you sadly and tell you to stay far, far away.

…

This story was just begging to be written. I do think that possessive/territorial is Danny's focus, like he has very definite and strong opinions about what's 'his' and stuff, and that's why he protects it so strongly instead of giving up when an enemy gets to the level Undergrowth did.

It was slightly depressing, but I can definitely picture this happening.

EDIT:

Some people have thought it unclear whether Phantom did something to Fenton, so I'm editing the A/N

Well, he didn't separate himself, he just made it look like Daniel Fenton was kidnapped/killed because he decided that he liked it better in his ghost form and could think clearer, because the ghost half's obsession was pressing on his human half's mind and causing him pain/clouding his mind. Making it hard to think straight. It also has to do with my theory that each time he gains a new power, it' ships ghost half gaining a bit more power over the human half.
Does that clear it up?

EDIT 2:

I just saw a theory where Danny's obsession is heroics, and that's why he's so powerful. That makes a lot of sense, and puts him in a more positive light. The more he is a hero, the stronager he gets.