so a Mermaid Sonadow AU of mine is one that I have wanted to write a fanfic about for some but I never found the motivation nor cared for the plot line enough to actually start writing it, so I’ll just post ideas here on how I would want it to be like along with some fanart
So the AU is about this underwater kingdom that I’m basing off The Little mermaid (Not exactly but similar) and basically, no one is allowed past the kingdom because of ‘sea terrors’ and such, and Sonic, who is a mermaid hedgehog (A merhog, if people want to call it that), decides that this is like being in a cage, so he decides to wander out of the kingdom just for a little while to explore a bit more of the ocean. There, he stumbles upon some ancient ruins and while adventuring, he stumbles upon another Merhog (Shadow) with some ‘unique markings’ and some ‘mutations’ that aren’t very noticeable, but he noticed cause it’s one of those ‘fall in love at first sight’ (I acknowledge that I am obsessed with those tropes) and he ends up talking to Shadow for a bit before dragging him off to the kingdom, believing that Shadow was some Merhog from different waters and traveled here and got mixed up.
However, Shadow is actually a Siren (I’m calling these ‘Hedge-Sirens’ or ‘Sir-hogs’) In this world, Hedge-Sirens and Merhogs are VERY similar, the only difference being that sirens have a more unique look with more unique markings, and the hypnotic song thing, along with some abilities to transform or cause illusions. Shadow was actually in the ancient ruins Because it belonged to his past siren group before most got killed by sailors, including his sister, who was actually a human Siren. He doesn’t normally eat sea-creatures, instead aiming for sailors just for some petty revenge for the sailors who killed his sister.
Anyways, Sonic Leads Shadow to the city and here it gets pretty blurry. I don’t know if I want the people to be like ‘Ah yes. A merhog. Moving on—‘, ‘Hmmm…suspicious, but still a merhog’ or ‘THAT IS THE DEVIL-‘ because some people still know Sirens exist (something to clarify is that there are myths of sirens that only old people believe in. Like those ‘I swear I saw a dinosaur when i was your age!’ ‘Okay grandpa’ kinda deal. If I choose this, then they’re gonna test it and Shadow Just sings Bad on purpose.)
Anyways, he ends up blending in for a while until one day, Sonic gets captured by sailors who want to make some money by selling Merhogs or just anything like Mermaids, and end up capturing sonic. Shadow is furious and hence, he uses a siren call and ends up drowning all the sailors before releasing Sonic. From here, I’m also conflicted on what to do. Like, would he be thankful but terrified or disgusted and terrified. Like, I personally think Sonic was one of those guys who were like ‘Sirens? Ha, big deal. ‘Tis nothing but a myth’ and now the guy he fell in love with is a siren.
so from here, I have one of two endings. The first is an angst ending where sonic feels disgusted and goes off, telling Shadow that he’s no longer welcome. And Shadow, not wanting to lose anything anymore, does what’s in his genes and just kinda kills sonic, dragging him under and killing him, which I would choose but I feel like it’s kinda out of character, and the second ending is where sonic is thankful and after talking for a while, Sonic accepts this and promises to keep it secret and they have happy relationship.
Anyways, that’s the end of my rambling.










