Undyne

[Undyne]

STORY AND BACKGROUND

Pre-Omniverse

[spoiler]
Pre-Undertale Events
Undyne was born and grew up in New Home, the enormous cavern region beneath Mt. Ebott where the Kingdom of Monsters existed. As a kid she once challenged the Monster King, Asgore, to a fight but could not land a single blow and found herself humiliated as all he did was dodge her attacks without fighting back. Asgore offered to train her after the fight and eventually promoted her to Head of the Royal Guard, which among others entailed the duty of pursuing and killing the humans that fell into the Underground.
Undyne also met Alphys sometime after the former royal scientist, Gaster, vanished and the drake replaced him after leading Asgore to believe that she had created a soul. Their initial meeting bloomed into a great friendship, though both sides kept their feelings concealed: Undyne had a crush on the cute drake. What she did not know was that Alphys had the same feelings for her, but wouldn't dare let anyone get close to her because of the many lies she had spun. Thus they remained what they were: great friends.

Waterfall Region
After Frisk befriended Papyrus and entered the Waterfall region, Undyne began her pursuit in spite of Papyrus attempting to convince her not to attack the human. Numerous times did she attack, attempted to corner her and once even broke off a large piece of bridge to send her plummeting to her death. Frisk survived everything and eventually made it through Waterfall. Eventually she confronted her at the entrance to Hotland and attacked her. Frisk proved tenacious however and fled the scene, to which Undyne gave chase into Hotland and eventually collapsed because her armor heated up in the high temperatures. Rather than leaving her to pass out though, Frisk poured some water over her, bringing her back to her senses. Confused and frustrated, she withdrew to Waterfall, the human now beyond her reach.

Undyne and Frisk's Hangout
But was that her last meeting with the human? Far from it. At Papyrus's suggestion, Frisk came to Undyne's house to hang out with her, much to her anger - had she come to rub her victory in? No... she wanted to become FRIENDS with her. She was about to kick Frisk out when Papyrus presented "becoming friends with Frisk" as a challenge, and her hot-headedness made her turn around. Papyrus saying that she wasn't up to the challenge? She was going to show him! They were not just going to be friends. They were going to be BESTIES. Frisk was going to be enamored with her, unable to think of anyone else! It would be the perfect revenge!
Long story short, the hangout started pretty decent but when Undyne remembered that Papyrus, who had bailed, was going to have his cooking lesson but wasn't there, Frisk was going to have it for him, it turned into a disaster (It ended up with Undyne's house in flames), but in spite of it all Frisk convinced Undyne that she could not fight her... and Undyne ended up accepting her as a friend, as she went to live in Sans's and Papyrus's house for a while.

Undyne and Alphys
A while after their hangout Undyne asked Frisk to deliver a letter to Alphys, in Hotland. Though there was a great many misunderstanding with Alphys believing that the love-letter came from Frisk because Undyne had not signed it, but after Alphys expressed her feelings about Undyne to Frisk and the fish-woman was nearby, searching for Alphys, heard everything. She was much happier about this than she openly admitted and thanked Frisk. While the human went to confront Asgore, Undyne met Alphys and they confessed their feelings to each other.

The last battle
Undyne was one of the many who interrupted the battle between Frisk and Asgore and demanded that they befriend each other. She nearly kissed Alphys that time, but was interrupted by Toriel, and later Flowey who ensnared them and sucked out their souls. She blanked out until her soul was returned to her and found that, during the blankout, the barrier imprisoning the Monsters in the Underground had been broken.
Being allowed to go free and with no further need to attack humans, the Royal Guard was disbanded, leaving Undyne free to go watch anime with Alphys. Having gotten out in the morning meant that they had the entire day to explore this new world, loving every second of it. The entirety of the one day of time that was allocated to them both.

The End...?
After making the most out of her first day on the Surface they went to sleep, and Undyne woke up not to the sight of a new morning, but in a black void with a white being grinning at her. His name was Omni, and this was not the world she knew.
[/spoiler]

In the Omniverse

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