With blessings from Allietheepic7, I hereby adopt Hiro Complex and make it my own. The concept is 80% the same, the story will be different, and I hope you all like it.

Warning: this AU features spoilers for the BH6 movie and the Danny Phantom cartoon series (especially from the episode The Ultimate Enemy), Older! Fem! Danny, Alive!Tadashi, possible slightly OOC characters, cameos, eventual merging of Danny Phantom and (possible) BH6 TV series episodes, OCs, culture mixing, angst, some PTSD, bereavement, witty banters, and mild fantasy violence.

PS: photo is roughly what Dannie's adult ghost form looks like. Will explain later. Sorry if it cut off her head and boots, I didn't mean for that to happen.

And now I give you: Big Hero Phantom (A Big Hero 6/Danny Phantom Crossover)

Chapter 1: Once Upon a Dream

San Fransokyo, north of its sister city San Francisco, an American city built post-WWII to unite the Americans of Asian (namely Japanese), European, and other racial and cultural descents after V-J Day. Over time, the city became a high-tech hybrid of artistic and technological architecture, being designed to better withstand the risk of earthquakes, and a fusion of both Western American and Japanese architectural styles. Even San Fransokyo's half of the Golden Gate Bridge is a hybrid-design of the original bridge along with a design of Japan's spirit bridges. Just outside the city's limits, in the Polo Field in Golden Gate Park, a camera crew followed a black haired super model in her early twenties, wearing a skin tight black leather jacket and pants with black knee-high boots, walked up to a new-looking blue and white Yamaha Ninja 650r sport motorcycle. The model turned her vibrant green eyes to attention at the cameras, gave a sexy bad girl smile, winked, and then put a black motorcycle helmet, completely covering her face.

The model having done her part, the director, a man with a bushy mustache in his mid-fifties, yelled, "And cut! Bring in the stunt double!"

The model removed her helmet, looking a little annoyed, and walked behind the camera crew with a huff. Another black haired, slender adult female, wearing the same outfit as the model, right down to the helmet, walked to the bike and got on it.

In the cyclist's internal soundtrack, she could hear the sound piece of NASA's rocket launching sequence, "3…2…1…"

"Annnnnd…. ACTION!" is what the director, while the stunt double heard, "And we have lift off!"

The stunt girl revved the engine and took to the cycling track, currently with added in obstacles for added affect. The cyclist bobbed and weaved past the cinderblock barriers, leaning very close to the ground several times. Time seemed to slow down, even stop as she zoomed through the man-made hurdles. She then reared up her bike and jumped over two logs as she made her first turn, feeling the wind against her body and spraying some of the camera crew with loose dirt—the camera men tried to shield themselves but to not avail. Then came the rhythm sections, irregular series of jumps with a variety of combination options; she zipped through those with ease before skimming along the tops of multiple bumps. At the second turn came the triple jumps, a stunt involving three jumps in a row that riders normally clear in a single leap of 70 feet or more. Revving up once more, she made each jump with little effort, once again time seeming decelerating to the point of stopping as she made the final jump. As she came to the end of her run, the stunt double pulled a Speed Racer 180 stop, kicking up more dirt.

"And cut! That's a wrap!" the director called while the girl heard, "Ladies and gentlemen, the Eagle has landed, intact."

The stunt double removed her helmet, revealing just how different she looked from the model. While the super model had a curvy build, styled hair, green eyes, button nose, and a heart shaped face, the stunt girl had out-of-control black hair with a stubby ponytail and bangs that always hanged in her face, a narrowed, friendly face, a pointed nose and large forehead, cheery sky blue eyes, and a body that lacked in height and curvature but made up in agility and an athletic built.

"Sorry about the dirt bath guys," the stunt girl called out to her dusty coworkers.

"Are you kidding, Fenton?! That was the best part!" the director praised in his usual fast-talking tone, "You're a natural! A prodigy! It's clear that you were destined for this!"

"Cuse me, but when I was asked to star in this commercial, I was under the impression that it would be about me and only me," the super model sneered, revealing her Russian accent, "Not this suka*. Why was I not to ride this bicycle?"

"Natalia, baby, darling," the director tried to explain, "You would've been perfect, fantastic, outstanding! But the producers decided to add the obstacle course at the last minute and that wasn't part of your contract and we didn't have the money for your insurance, so we had to call in Danielle."

"And this isn't a bicycle," the stunt girl politely pointed out, "It's a motorcycle."

"The only consolation to this waste of time," the model glared, "Is that it is my face the world will see, not yours, Bolvanka**."

Danielle looked at the older woman as the latter walked away, not knowing whether or not to be insulted, saying, "I'm actually okay with that. And it's Dannie."

"Well, in any case," the director changed the subject, handing her two checks, "Here's your paycheck, plus a bonus for the last minute call."

"Can I have the bike instead of the bonus? I've always wanted one of these."

The director laughed until he had to wipe a tear from his eye. Then he put an arm around her shoulder.

"You know why you're my absolute favorite, Fenton?"

"Because I have great reflexes and zero drama queen habits?"

"No, because you're cheap. Take the bike! I'll have the registration sent by mail."

Dannie thanked the director has he patted her shoulder and ran back to her new ride. She hopped on and drove off. Lean towards one of the trailers, she grabbed a white colored bicycle helmet with a ghostly black "D" and inner "P" sticker on the side and put it on one handed. Driving east, she made her way back into the city, careful not to break any laws.

"Hard to believe it's only been five years," she said to herself as she stopped at a traffic light.

Five years ago, almost to the day, the young woman had lost everything: her parents, her sister, her friends, one of her teachers—to be honest, she didn't really care that he was gone but no one deserved to go the way he (and all the others) went—but most importantly, her remaining childhood; all by the hands of a very powerful and very sociopathic being. Fortunately, said being was gone forever, unfortunately Dannie Fenton had to virtually disappear to keep her from coming back. She could've chanced it, but her would-be legal guardian wasn't right for her, so, after setting somethings right and grabbing what she could carry, the then fourteen year old girl spent four years on the run, staying away from the man until she was eighteen, legally an adult and therefore can stay as far away from him as she wanted.

Another stoplight later, an icy blue mist escaped from her mouth. Her brows furrowed and her eyes turned neon green: there was only one reason for that during a Californian September.

"If this is another one of Plasmius' spies, I'm gonna go ballistic," she muttered under her breath.

Looking around she saw a hospital to her right; turning her blinker on, she turned into the building's main driveway and parked her bike in the visitor's space. Dannie followed her instinct, turning invisible and snuck into the hospital, momentarily reminded of the time her old school's entire student body came down with a "ghostly illness" and were falsely quarantined so that one of her enemies can have a genetically engineered fountain of youth. Shaking her head of those thoughts, she continued her search. After some trial and error (mostly error), she eventually found her quarry. In a room, in the coma ward. Joy.

Danny became visible again as she cautiously entered the room. Laying on the bed was a young man around her age, half his face along with his chest, his left leg and both arms wrapped in gauzy bandages, hooked up to a half empty IV bag and several monitors, wearing nothing else but a pair of hospital pants. An oxygen mask covered his nose and mouth, he seemed to breathing on his own, however weakly. Out of the corner of her eye, she saw a barely discernible spectral version of the patient pacing back and forth on the right side of the bed, his head down and looking miserable, defeated, pitiable, and kinda cute. The entity didn't acknowledge her, whether he heard her or not. His spirit form flickered every few seconds.

Walking over to the end of the bed and looking over the medical information on the John Doe, she let out an astonished whistle, looked over her shoulder and said, "I'm surprised you lasted this long."

That got the specter's attention as his head whipped in her direction, "Excuse me?"

Dannie mentally took back the "kinda cute" observation she made earlier, this guy was really cute. Physically fit, neat hair, wearing a causal/professional attire, and very handsome despite of the light burn scarring on the right side of his face, his big amber eyes— currently filled with shock and confusion— reminded her of an adorable puppy.

"Oh, sorry, just thinking out loud," She awkwardly replied, looking directly at him, "I was just surprised you lasted two months. According to…. a person I met, most out of body experiences end with the spirit moving on or returning to its body after a couple days..."

"Wa-wa-wait," the specter interrupted, walking up to her, "You…you can see me…You can hear me…"

He tapped a finger to his chest, repeating, "Me."

"Y-yeah," Dannie nervously answered, "I can."

The specter stared at her for a moment then a huge grin formed on his face, soundless laughter coming out, his eyes lit up with… hope. No one ever looked at her like that. Shock, surprised, fear, anger, disgust, hate, indifference, joy, concern, but never hope. Then again, considering this guy was on the verge of doing a back flip, being heard and seen after two months was probably the best news of his life.

The young woman put a hand on his shoulder, only for it fall through his body and back at her side. Okay, that was a little embarrassing, the first person to finally see or hear him tried to give the first tactile contact in weeks and failed epically.

"Sorry," she quickly said, grimacing.

The man gave a weak laugh and responded, "That's okay; I'm used to that."

"I'm Dannie, by the way. Dannie Fenton."

The specter stammered, too excited to think, "My… my name's Tada…Tadashi H-Hamada."

A/N: Like in Allietheepic7's original story, Tadashi's not dead… yet. This is an alternate universe where (as well as having a female Danny Phantom who lost everything in TUE) he survives but ends up in a coma and is labeled in the hospital as a John Doe since he doesn't have a record (and therefore no DNA or fingerprints in the system) and the doctors felt it too risky to make a dental mold on him. Therefore, everyone who would've known him never got the call to identify him and thinks he's dead allowing the BH6 movie to go on as it did, a sad but necessary development for Hiro to, well, develop into a responsible adult. Don't worry, there'll still be a reunion.

The main backstory difference between my version and Allietheepic7's version is, as stated in this chapter and to be further stated and elaborated in future chapters, after the Nasty Burger explosion, Dannie almost ended up with her arch enemy as a legal guardian via her parents' will. While aware that the alternate future was her fault, she still decided to avoid him like the plague because he's a bad guy and as a hero, Dannie doesn't associate with criminals (Wulf being an exception because she doesn't regard Walker as an actual law enforcer, just a creep that lives to make others suffer.) So she ran away after retaking the CAT (will explain later), destroying the ghost portal along with her parents' more dangerous equipment, and grabbing some stuff (including some of her parents' patents). She travelled the world until she was eighteen, then she settled in San Fransokyo and became a stunt double because NASA shut down the astronaut program (as they did in real life).

From what I saw in the police station scene, Hiro found out about the micro-bot theft sometime in July, so assuming that the Expo happened sometime in late June or earlier in July and the "Krei Tech Attack" (as I'm calling it) happened sometime in August, I'm estimating that this story is happening in mid-to-late-August/ early September.

Side notes: here are the translations for the insults directed to Dannie:

*=slut

**=slughead