Disclaimer: I never actually played Undertale but I've seen lots of playthroughs regarding all ends. Please don't kill me. Also I don't own Undertale. All Characters belong to Toby Fox.

Undyne had been chasing the human that called herself frisk for a good long while. Truth was there was about the human that seemed to have a kind of untapped strength. Was it magic, was it DETERMINATION, she didn't know. Racing across the mountain top, the young warrior knew that nothing was going to stop here. She was going to be the hero that the underground needed her to be, even if that meant that she'd have to chase the human for eternity.

Undyne looked down and noticed that Frisk was directly beneath her. She crouched like she was scared or trying to hide. Undyne took a deep breath and raised her spear.

"That's it then. No more running away….HERE I COME!"

Frisk managed to barely dodge the spear. When Undyne landed one the ground the earth shook and cracked as if a great earthquake had been summoned.

"En Gaurde!" the captain shouted.

At first frisk tried to flee but with a flick of Undyne spear an ethereal green aura engulfed frisk's body. Undyne let out a haughty laugh.

"As Long as you're green you can't escape. Unless you learn to face danger head on, you won't last a second against me." The Warrior then summoned three glowing arrow like spears.

Frisk knew what that meant. After all Undyne had been trying to show her what to do for the past two and a half hours. She was not stupid. What she wanted to know was when was this fish woman going to get it through her thick gills that Frisk didn't want to fight? The last time she fought a monster she lost control and had it not been for the fact that she managed to reset, said monster would have been nothing but dust as she spoke.

But it seemed like this Undyne was not giving her much of a choice. Reluctantly she took out the spear that the captain had given her early and began blocking the energy arrows. She then lunged at Undyne managing to strike a small blow across her arm.

Undyne she her fist murting a small yes. Finally she was going to get the fight that she had been dreaming of.

"Not bad but how about this.

More arrow spears came but frisk once again did the same block and attack.

A Cheshire-like grin came over Undyne's face as she slid her clawed hands across her neck in a cutthroat motion. For a while, this was how the battle was. The same motions became almost like clockwork. Undyne gave a speech as the battle progressed.

"For years we dreamed of a happy ending, and now sunlight is just Within our reach. I won't let you take that away from us. Everything we have worked for, everything we have suffered for has been leading to this moment. I have gone too far, we have gone too far just to fail now. My friends are counting on me to protect them, and I will fight with ever last inch of determination. Even if it means my very soul splits into a million pieces."

Gritting her teeth, Frisk charged. The spear sank into Undyne's left shoulder. The warrior let out a grunt before pulling the spear out and pushing Frisk backwards. Undyne let out a smirk. She was actually impressed.

"You know. Your kind of tough, but even if you defeat me, you'll never get past Asgore. If you think I'm tough, you haven't seen anything. In fact, killing you at this point would be an act of mercy.

As the battle Progressed, the movements began to feel more and more natural for Frisk, in fact not only was she feeling comfortable with it, she was getting into it. That feeling of dodging every obstacle that the warrior through at her. Leaping and sliding across the field like some sort of sort of Superhero. It felt Awesome. It felt Amazing. It felt…Addicting.

"This is it This is what we were meant for. This is our story. We're the hero"

Each attack gradually got more daring and more damaging. With every turn Frisk was getting braver and more ferocious. Undyne while a first caught off guard began cackling trying to goat the young girl. This was it. This was the battle that she had been waiting for.

"You know, Alphys told me that humans were determined. She wasn't kidding." She then raised her spear up to the sky. "But I'm determined too. I'm determined to end this right now."

Undyne Unleased a Flury of attacks. But Frisk was not going down.

"Right now…" Undyne gritted.

Try as she might, Undyne's attacks seemed to be futile against the human, and where she was weakening, Frisk was just getting stronger. she found herself desperately being put onto the defensive. That was until she felt the burning pain of the spear being forced through her stomach.

"NAUUNGH! You…You were stronger than I thought.

She collapsed to one knee, but her balance started to fail her as her body started to dissipate.
"So…This…this is where it ends. "

Then something inside her clicked.

"No…NO! Alphys, Asgore, Papyrus, I won't fail them!"

Her body instantly revived itself. Her eye dilated becoming black and Shark-Like

"Human in the name of everyone's hopes and dreams I will defeat you!"

Now it was something in frisk that was changing. She gritted her teeth snarling almost like some kind of demonic beast. Undyne found herself a bit startled. For a split second, Frisk's face changed. Her Eyes changed from blue to a deep crimson red, and her teeth were almost dagger like. It didn't last long enough for Undyne to focus on it, but it was enough to startle her.

"What…are you?"

Frisk lunged forward and stabbed Undyne in the leg. Now the pain was unignorably. She yelled before once again collapsing to one knee, Which once again began to dissipate. But then she smiled

"Is that the best you got? You are going to have to try harder!"

Each attack got worse and worse. First the legs, Then the shoulders and try as she might Undyne couldn't keep going like she was and she knew it.

I can't…can't give up."

She summoned one last energy spear chucking it at frisk who blocked it off with an impatient grunt. Frisk then flipped the spear straightening it. With a mighty throw the Spear zoomed like a bullet impaling Undyne right through the chest.

The warriors breath left her she found herself gasping tears stemming down holding back the shock. Her body began to split apart almost immediately

"Alphys…this…this is what I was afraid of. This is why I never told you…"

As Undyne spoke, Frisk shook her head snapping out of her rage like state. Once she realized what was happening, tears started dripping from her face. She dropped the spear before collapsing herself.

"No please No, Not again.

Undyne Gritted her teeth "No….NO! I Won't die."

With a mighty war cry, Undyne's body snapped back into place A look of aw and hope came over frisk face….She hoped maybe Undyne could triumph over this. Maybe Undyne had the kind of determination she did. her look of hope quickly however turned into a look of horror. The strain on Undyne's body was too much. It literally began melting like wax from a candle. Undyne felt herself slipping away, but she refused to go down quietly. Her voice became slower and more slurred.

I Won't…die…I…Won't…Die…I…Won't

Undyne's mind all of the sudden jolted back in to focus as she finished her sentence.

"…Die?"

Her whole body felt numb and cold. She looked down at her hands realizing they were fully intact as if they had never been touched. Looking at her surroundings she realized that she was on top of the mountain again. She looked down below seeing what appeared to be Frisk looking back at her body trembling.

"What the heck is going on?"

The two of them just battled. Undyne nearly died. she felt herself dying, and then all of the sudden she just…wasn't. A mixture of feelings began to creep into Undyne. Fear, confusion. She felt like she had just been violently jolted out of some hyper-realistic nightmare, but that battled occurred was real…or at least it felt real.

The young warrior grabbed her spear. This time she slowly crept down the mountain.

Frisk was knocked off guard. Something was not right. Anytime frisk had reset before, the monsters would just continue their pattern of behavior. Truth be told she had expected Undyne to do her weird spear dive attack, but she didn't. Instead the warrior just slowly climbed down the mountain before softly landing on the ground.

Undyne's legs shook as she cautiously approached Frisk. Undyne wanted to lift her spear, but for whatever reason whether physical or psychological, her strength was gone. She stopped about two feet from the Frisk. Her breath was shallow and timid.

"What did you do?" The warrior whispered.

Frisk through down the spear and attempted to bolt.

"Wait!" Undyne shouted.

Frisk stopped in her tracks before turning around looking like a deer in a headlight

"What did you mean by not again?"

Frisk breath stared to rapidly increase. Tears started to flow from her eyes. Everything, the sudden timid change in Undyne's behavior the question. It only meant one thing. Undyne knew that Frisk reseted things. Unable to keep her composer, Frisk fell to her knees and sobbed.