Please explain everything about this AU I know you'll like it
:D!!!
Okay, Fishdings is basically an AU where Gaster is Undyne's dad and his name is Fishdings Angler!
He's still the royal scientist though, he works for Asgore and specialises in multiversal studies, coming up with ways to bust out of the underground, the CORE, SOULS and whatever mechanical bullshit the adhd mindset decides he should build today.
The canon Gaster followers are, of course, his coworkers, as are the Goners.
He had a sister named Shelley (a geologist) who reproduced via asexual reproduction twice. She had two daughters who she named Shyra and Shyren. Sadly, not long after she created Shyren, she was killed by the JUSTICE DETERMINATION child, Caper.
Oh also here's a list of the fallen human children and their soul powers:
Chara: Determination (i think)
Idyll: Patience
Antic: Bravery
Spice: Integrity
Llark: Perseverance
Caper: Justice
Revel: Kindness
Frisk: Nothing (get rekt, despite everything u continue to just be urself)
Despite mourning his sister, Fishdings was also jealous that she had children and decided he should attempt to carry out something similar! He set up in the lab basement a là powerpuff girls, and combined the powers of HIMSELF*, RAW COSMOS AND GOLDFISH CRACKERS! He was content with this mixture, but OH NO! he accidentally knocked in a flask of LIQUID JUSTICE DETERMINATION, a lá powerpuff girls! (like I said, he was studying souls)
*(he can use magic to shift between having legs and having a fish tail, and mid shift it's goopy. He used a lump of this goop)
From this mixture a five year old child sprung fully formed and immediately attempted to fight her creator. And won. Fishdings was very very proud of his five minute old daughter and immediately took her to his boss so she coukd get lessons in combat. While she attempted (and failed) to beat the living shit out of Asgore, he came up with the perfect name: UNDYNE.
Once Undyne got too tired to keep attempting to fight, Fishdings decided to take her to see her relatives. They took the ferry (obviously) and Undyne got to meet her honourary uncleaunt Riverperson.
Riverperson has legal custody of Shyra and Shyren (they and Shelley were inseparable when she was alive), but as they are busy ferrying people around half the day (and trying to build a bigger boat) they mostly leave the girls in the care of the Blooks.
Undyne meets her cousins and their babysitters: Maddy, Blankstablook**, Napstablook and Hapstablook. Maddy, the eldest at 13, is the only one who actually babysits (the others are no help) but all of the ghosts insist they babysit too.
** Blankstablook is the ruins dummy
Shyren, one, is excited to meet her new cousin and they are fast friends. They frequently run around the house together screaming. Shyren is a very musical baby and Undyne just likes yelling.
Shyra, six, is... less fond of Undyne. As her mother was killed by the justice child and Undyne is made of justice determination, she resents her new cousin a little. She eventually warms up to her though, and they grow up very close.
Shyra and Shyren live in the house that we know in the game as Undyne's, in Waterfall. The Blooks live literally right next door, making babysitting convenient. Undyne spends half her childhood here when Fishdings is busy with science stuff.
Undyne and her dad live in the top floor of the lab. It's really just a bed crammed into a corner with various photographs pinned to the walls around it, but there's a tv in the basement. So. Undyne is free to run around the lab as long as she doesn't touch anything dangerous. The other scientists become quite fond of her over time too.
A few years later, Fishdings decides that Undyne is getting too old to live in the lab with him, so they buy a house in Snowdin for Shyra, Shyrup*** and Riverperson and move into their old place. The Shy sisters are okay with this! Snowdin has way more kids their age, and there's a schoolhouse so they aren't alone at home all day. The Blooks are happy to make the trip to visit sometimes too.
*** Shyren discovered they're non binary and so is Shyrup now
When Undyne's 15 her dad falls into the CORE. How? Not sure yet. Anyway, Undyne is so filled with JUSTICE DETERMINATION her hair glows gold and she vows to find him. It takes a few years, but they eventually figure out he's trapped in the void, build a portal and send a now 17 year old Undyne in to get him out.
The only problem is Fishdings is now liquid. He lives in a vat for a while, until he's eventually solid enough (slime consistency) to move around on his own. He immediately commissions a giant fish tank on the top floor of the lab, fitted with the void portal in the corner and takes to doing multiversal/void research in there.
The other scientists are relocated to a bigger lab in New Home so Fishdings can leave his slime and half built portals all over the damn place but they still visit sometimes! Fishdings visits the other lab sometimes too but mostly stays in a fishbowl on wheels so to not drip on the carpet.
Another year or so later, Fishdings gets word of a young scientist named Alphys who built a fabulous robot, that now has his own tv show. He arranges a meeting with her and hires her on the spot, giving her free run of the basement for whatever science related shit she pleases. He allowed her to use the basement because he wasn't using it, definitely not because he saw Undyne making heart eyes at the lizard monster...
Not long after that, Shyra "falls down". Fishdings and Undyne are devastated, and Alphys vows to find a way to revive Shyra and other monsters who have suffered the same fate.
The amalgam incidents carry out as they did in canon, except this time Fishdings finds out about it. It's difficult to hide four (five? six??) goop monsters in the basement when you have another goop monster two floors up who likes to pop down sometimes (nosy).
He encourages her to come forward about it, so the Amalgamates are returned to their overjoyed (albeit slightly confused) families. Undyne and Shyrup are, of course, overjoyed to have Shyra back! Except now she's also Moldbygg and Aaron, and goes by Baked Bread.
Two humans fall into the underground when Undyne turns 24. Their names are Revel and Frisk. Will they kill everyone or will they be pacifists? Depends which fanfic Killer and I will eventually write you read...
...
So yah. Other than Gaster being a fish and present and Undyne's dad and the amalgams being free and sans not existing and Shyrup and Baked Bread being very very relevant, not much else changes.
There are aesthetic changes ofc: Fishdings puts fishy motifs into everything he creates, and being head scientist means the rest of the Underground take to using fishy motifs in their everyday lives.
Fishdings made the puzzles in the ruins (he used to go down there to visit Toriel before she decided to close it off altogether), so they also look fishy. His puzzle skillz inspired Shyrup to make a few music themed ones of her own in Snowdin. Fishdings made a lot of the puzzles in Waterfall and Hotland too so again, FISHY MOTIFS.
Mettaton is Mermatriton bc he and Alphys were too inspired by the overabundance of fishiness.
Um that's all I can think of to say for now, oh expect in the fanfictions Killer and I will eventually write, the SOUL controls Revel on pacifist and Frisk on geno. So yeah!
Sorry this took a few days for me to answer lol, had to spent a while typing.
