Okay, so Fishtail is slightly overpowered but he does have a major flaw/weakness as you'll find out in this chapter.

Thanks to a friend of mine from school for the salt idea early in this chapter!

I don't own Danny Phantom.

Danni regained consciousness while lying face down on a carpet. She recognized it too. It was the carpet she had in her bedroom. Huh, she must've fallen out of bed. She looked up and spotted a familiar face—Fishtail—and it all came back to her.

She stood up, eyes glowing a bright ectoplasmic green. "You—"

The half-merman grinned. "Sorry, you can't move forward to attack me."

Danni looked down at her feet to see something surrounding her in a circle. Was that…

She raised an eyebrow and looked at Fishtail. "Ha ha, very funny," she laughed dryly. "Oh no! You've trapped me with salt!" She put a look of mock horror on her face.

Fishtail nodded. "I borrowed a book from Sam. Sure she's in Paris, but I've got superpowers! There's no limits. Anyways, this book says that salt can trap ghosts."

Danni rolled her now-icy blue eyes. "Salt?"

He nodded.

"Really? Salt?"

Another nod.

She chuckled and stepped over the barrier. Fishtail's face became one of absolute horror.

"B-B-But…" he stuttered.

Danni's eyes glowed as she raised a hand and used telekinesis to drag the book that he had borrowed towards her. She took a pen out of her pocket and scribbled something down before handing the book back to Fishtail.

He took it quickly as if the halfa girl was poisonous. She had crossed out "salt" on the list of things that contain ghosts. It was replaced with "blood blossoms" in chicken scratch handwriting.

He dropped the book and took a step back. "S-S-STAY AWAY FROM ME!" he screeched.

Danni snorted. "I'm not evil or toxic, Fish Boy. I'm you from another dimension."

Fishtail froze. "What?"

A groan interrupted their discussion. The half-ghost girl and half-merman boy turned to see that Danny had woken up. The halfa got up and growled at Fishtail.

"You!"

An ectoblast was quickly thrown. To both boys' surprise, it was their female counterpart that stopped them. She was rapidly in front of Fishtail and had a mirror shield thrown up. The blast was deflected and sent back at Danny, who got hit with it.

"Enough! Both of you!" she yelled in her I'm-Danni-Phantom-and-I'm-in-charge-voice. "I think we've had enough of attacking our alternate dimension selves.

"He started it!" each male yelled, pointing at the other.

"I don't care!" Danni hissed. "Now, let's go back to formal introductions. I'm Danielle Fenton AKA Danielle Phantom of Dimension 2 but you can call me Danni."

Danny glared at Fishtail. "Daniel Fenton AKA Daniel Phantom of Dimension 1. Call me Danny."

Fishtail rolled his blue eyes. "Fine. I'm Daniel Fenton AKA Daniel Fishtail of… what dimension is this?"

"Dimension 3," Danni said.

"…of Dimension 3 and you can call me Fishtail since Danny is taken. But call me Fish around humans besides Sam, Tucker, Jazz, Danielle the clone, and Vlad." Fishtail rolled his eyes again.

"There. Was that so hard?" Danni said. Her voice quickly changed to her You're-My-Enemy voice. "Now, Fishtail! What did you do to me and Danny?"

The merman halfa leaned against his dresser. "I simply drained your energy and used it for myself. I drained enough to knock you both out." His eyes glowed full green. "If you want, I can drain enough to kill you."

Danni's gaze hardened and she abruptly vanished. Needless to say, Fishtail freaked.

Suddenly, he was grabbed from the back of his shirt and spun around so his eyes met the radioactive green ones of Danni Phantom.

"Listen, Fishtail," she hissed, jabbing him with a gloved finger. "We don't want any trouble. We're looking for Danny's alternate future self who came to this dimension and attacked you…How long have we been out cold?"

"About an hour or two," Fishtail stated, absolutely terrified.

"…Who attacked you earlier today." A smile lit up Danni's face. "But I think I know why he did it."

Danny rolled his eyes. "No, genius. He practically shouted it to us."

Danni dropped Fishtail and started to pace. "Dan said he want revenge. Revenge on whom? Danny. But he can't kill Danny since if Danny goes he goes. But you and I, Fish, are free game. He can do whatever he wants to us and nothing will change with him. He taking out his anger from Danny on us! And he will kill us if he needs to."

Fishtail looked down for a second, black hair masking his face. When he looked up again, determination filled his icy blue eyes. "I'm in."

"What?" both ghost hybrids asked confused.

Fishtail smirked and folded his arms. "I'm going to help you defeat Dan. Even if it means travelling through another dimension and potentially dying."

"What?" the duo repeated.

"I'm not letting someone else die for something I can die for," Fish specified. "I'm a hero. It's part of my hero complex."

Danny smiled and held his hand out face down. "Dimension Chasers."

Danni and Fishtail looked at each other before putting their hands in. "Dimension Chasers."

"Danny! We're home!"

Fishtail's eyes widened. "Crud! I forgot Mom, Dad, and Jazz were coming home early!" He shoved the two ghost hybrids towards his closet. "The entrance to my grotto is in there."

"Grotto?" Danni repeated.

Fishtail rolled his eyes. "It's my second home in the Merfolk Zone. Don't worry. It has air."

"Kind of like our lairs!" Danny said as he opened the closet to find a blue door behind Fishtail's clothes.

The half-merman opened it. "I'll see you in the morning." He shoved the duo inside.

….

Danny did not want to get up. Neither did Danni. So they both lay in Fishtail's grotto completely awake, Danny on the couch, Danni on the bed which so happened to be in the same room.

"Remember what today is?" Danny asked.

"Yup," she responded.

"It's been a year."

"A very long year."

"We've both done a lot."

"Yup."

Fishtail chose that moment to burst into the room. "Wake up, you half-dead dweebs."

Danni buried her face in her pillow. Danny buried his in the couch cushions.

"Did I miss something?" Fish asked, confused. "That happened overnight?"

"Remember what happened a year ago today?" Danny asked.

"Yeah, when I climbed into the Fenton Merfolk Portal and turned into a hybrid between merman and human."

"Well, it's the same thing for us," Danni explained. "Except it's called a deathday. For full-fledged ghosts it's the anniversary of your death. For halfas, it's the anniversary of your half-death. It's a pretty serious thing. Ghosts ignore the deathdays of halfas, except they're not allowed to fight us or insult us, but full-fledged ghosts usually have a big party."

A smirk lit up Fishtail's face. "Well, I am technically a halfa, except I'm a merman one instead of a ghost one. So we're going to have a party of our own. Halfa style."

…...

Floody Waters was the local outdoor waterpark. Well, it was outdoors until the merfolk attacks became more common. Fearing the citizens' lives and the park's reputation, the owners decided to tear it down and build a new indoor Floody Waters.

"Welcome to the new and improved Floody Waters!" Fishtail said, holding the door open for Danni and Danny. "I usually avoid this place because, you know, half-merman and water." He shrugged. "Anyways c'mon. It's time to have a party!"

His excitement was cut short when twin wisps of blue air escaped the two Phantoms' lips.

"Ghost sense?" Danny asked. "There's no ghosts here except… Dan! And it appears that he doesn't follow the deathday rule."

Danni nodded. "We'll split up. Fish, you stay here. I'll go over by the snack bar and Danny'll go over near the lockers. Go!"

They immediately split. Danni ran her way to the snack bar.

And unfortunately bumped into someone, causing them both to fall down.

"Ow!" Paulina Sanchez moaned as she rubbed her head. She glared at the halfa across from her. "Who exactly do you think you are, freak?"

Danni winced slightly. She hated being called a freak. She decided to ignore the Latina and pulled her hair up into a loose ponytail.

"At least give me a name, loser," Paulina demanded.

Behind her sunglasses, Danni's eyes flashed neon green. The girl was seriously pushing it. "I'm Danni. Spelt D-A-N-N-I. Sorry for bumping into you."

Paulina got up. "Are you new here?" she hissed.

"Actually, I'm temporarily staying with a family member," Danni lied, getting up too.

"Well, I'll leave you with a warning, klutz," Paulina hissed. "I'm queen bee here and you don't want to mess with me."

A blue wisp flew out of Danni's mouth again.

Bam!

A wall crumpled and fell. Everyone coughed but gasped as a black shadow walked out of the dust.

The Dimension Chasers muffled gasps. It was Dan.

"Hold it!" a security guard yelled, holding a gun up to the futuristic demon.

"You're trying to kill me?" Dan said, raising an eyebrow.

The man fired. Dan went intangible at the last second.

"You can't kill what's already dead."

Everyone went into a panic, running and screaming out the door. Three teens stayed behind.

Dan lifted the security guard up by his throat. "I could kill you right now…"

"LEAVE HIM ALONE!"

A ball of solid ice hit him in the head. He dropped the security guard, who got up and ran out the door. Dan growled and turned around to see Fishtail standing strong, fists clenched at his sides, fingers webbed, as his eyes faded from neon blue to icy blue.

"The merboy?" Dan chuckled. "Oh please. This is almost too easy."

His booted foot slammed into the halfa's gut and pushed him backwards. Fish teetered at the edge of a pool, attempting to regain his balance, but ended up falling in anyway. His webbed hand was the last thing to sink under.

An ectoblast slammed into Dan's side. He looked up just in time to see his past self running at him in human form, a slight green glow around his fists. The teen slid to a stop and shot some ice and Dan. It hit dead on (no pun intended) and the future ghost slid backwards before leaping into the air and hovering over a pool.

Danny froze the pool and quickly ice-skated over to Dan and leapt into the air.

…Only to be caught by an ecto-goo rope.

"Oh, please. Too easy," Dan said with a yawn. "I'd think you'd be more of a challenge."

Danni gasped silently before noticing a rope attached to the wall above Dan's head. She traced the rope all the way to the opposite wall, which was on her left. Just before the wall, a few feet before, a Floody Waters sign hung on the line. She turned her head to find a sharp knife on the snack bar. An idea formed in her mind.

Dan examined Danny closely. "Wait a second, wasn't there a girl with you too?"

Danni stood away from the rope between the sign and the wall, aiming the knife. She had one shot at this.

The female Phantom drew her arm back and put all of her ghostly strength into a throw. The knife went sailing towards the string.

It cut through it like it was a piece of wet toilet paper.

Dan noticed the sign flying straight at him and only managed to drop Danny before it hit him.

"Actually, yeah, there was a girl with Danny," Danni said with a grin. "And that girl just kicked your butt."

The ecto-goo rope on Danny dissolved. A webbed hand gripped the side of the pool as Fishtail in his merman form surfaced.

"Huh, so you're necklace isn't a P in a D, it's an F in a D!" Danny realized. "That makes much more sense."

Fishtail glared at him. "Just get me out of here, ghost boy."

Meanwhile Danni approached Dan, who was sprawled out on the floor near the wall.

"Don't you know the rules for deathdays?" she hissed.

He got up and grabbed her chin before forcing her to look him in the eyes. "Don't you know that I don't follow the rules?" he hissed.

She only glared.

He slammed his fist into her face.

Danni was sent flying back before she was caught by Fishtail, who had dried off and was back in his human form.

"Oh, so now you join the fight," she said, voice dripping with sarcasm. Danny walked up besides the two.

"Since I haven't been able to get my revenge yet, it looks like we're going to have to go to yet another dimension!" Dan laughed. "Sayonara!"

He quickly opened another portal and jumped through it. The Dimension Chasers followed a second later.

Next chapter will have yet another Danny! And yes, the deathday part will come in handy in finding him. He's the second to last Danny, the shyest and quietest as well as most timid but he's smarter than the rest and sometimes can be a big ball of angst that you just want to give him a hug and I'm rambling aren't I?