An Anthem for Sheltered Bays
is a Attack on Titan Alternate Universe Fic on Archive of Our Own. The story begins when Levi returns to his and Hanji's private island from their comrade Petra's wedding. A storm hits on the way, causing Levi's boat to capsize. He nearly drowns when a mermaid named Eren Jaegar saves him.
Also available here but the author only updates the AO3 link.
Warning: Not Safe for Work as it has scenes of explicit sex, also SPOILER-ALERT, it contains unmarked spoilers from the manga You Have Been Warned
Tropes:
- Accidental Proposal: Since Levi made Eren trade six of his scales for his mantle, Eren believed them to be engaged since merfolk only trade scales for a marriage proposal. He is quite embarrassed when he realizes this isn't the case. They end up marrying anyway.
- Anywhere but Their Lips: After hearing Eren's singing, Levi ends up kissing and biting everywhere else on Eren's body, only for Eren to stop him when he tries to kiss him on the lips.
- Big "NO!": Eren lets out several of these when Levi won't let him leave to die and tries to fight him off.
- Body Horror: the titan found in the forest outside Dauper Village is mass of limbs and faces made out of the entirety of the village and the local beasts. What's worse is the people permitted it in an attempt to become gods.
- Bridal Carry: How Levi cared Eren before the latter learned how to walk.
- Call a Rabbit a "Smeerp": Mikasa, Armin, and Eren believed a fork to be a broken shell.
- Chekhov's Gag: Eren's nickname "Princess" especially when he shares a surname with the head of the project and the first successful mermaid.
- Convenient Coma: Eren goes into a coma after being forced medical attention and ended growing human legs.
- Crazy Jealous Guy: Levi is very possessive of Eren, hoping that the latter will never be able to return to sea
- Culture Clash: A lot of it since mermaid customs and human customs are very different.
- Deadly Euphemism: The extremely ill Eren tries to tell Levi that he's finally going home and that he's sees better at night. Since Eren was too weak to move, Levi doesn't believe him.
- Death of the Old Gods: Queen Historia's reign marked the end of the old church and worship of the old gods were abolished.
- Dented Iron: Eren's scales are so tough that knives can't even dent them but his wounds from the boat debri get infected and drives Eren into a slow death before Levi and Hanji intervene.
- Doing In the Wizard: Mermaids, harpies, werebeasts and titans are products of genetic engineering that escaped.
- Dreaming Of Things Gone By: In his coma, Eren dreams of how his friends and how he was driven into finding the surface and his perspective of his first meeting with Levi.
- Elephant in the Living Room: Both Eren and Levi deny that Eren's condition is slowly getting worse and that his tail hasn't healed at all, choosing to believe that Eren will eventually leave.
- Emergency Transformation: Since Eren is part human, Hanji saves his life by cutting off his infected tail and making him grow human legs in their place.
- Expecting Someone Taller: Based on Hanji's description, Petra expected Levi's fiancee to be an actual princess only to be surprised that he's marrying the young Eren.
- Facial Horror: Eren nearly scratches Levi's face off to the point that Levi is blinded by his own blood when he forces Eren to get medical attention
- Faeries Don't Believe in Humans, Either: Eren is made fun of by Jean for believing humans exist. This is deliberately cultivated by the village elders who want to deny their former masters and to convince everyone that they have always done this.
- For Your Own Good: Levi breaks both of Eren's arms in order to get Eren to comply to medical attention when Eren claws his face so he can get away and die.
- Friendly, Playful Dolphin: The first things Eren meets when he finally hits the surface, who help clarify that humans live on the surface not in another ocean and wanted Eren to play with them.
- Gender Rarity Value: In Ymir's village, the population was mostly women with the few surviving men be extremely old.
- Genetic Engineering Is the New Nuke: Mermaids , werewolves, werebears, harpies and titans were creations of old religion to serve as weapons in the war.
- Give Away the Bride: It's a double tradition, since Eren and Levi have no parents Hanji and Erwin give them away at their wedding.
- Going Native: Eren assimilates in human society with the help of Levi and Hanji after he is forced to become human to save his life.
- Healing Vat: The swimming pool served as one for the comatose Eren.
- Heroic BSoD: Eren has a small one after the Dauper Village titan gets put down.
- Heroic Willpower: It allowed Eren to survive his Emergency Transformation into a human, this is why the people of Dauper Village can't turn back human after being merged into a Titan. They would mostly like die in the attempt.
- Hidden Elf Village: The Superior Sea, the merfolk village Eren is from, were highly superstitious, abhorred fighting to the point they don't know what war is and where successful products of genetic engineering that denied human existence afterwards.
- How Dare You Die on Me!: When Eren tries to hide the fact he's dying by leaving, Levi forbids him from leaving and order him to not to die as long he's by his side.
- Humans Through Alien Eyes: When Eren first meets Levi, he mistakes Levi's mantle for skin and is horrified that he removes it, thinking he grievously injured him.
- Humanity Ensues: Eren becomes human after his tail gets cut off and his legs grow in.
- In the mermaid and harpy communities there is a potion that triggers the transformation into humans. Ymir's feathers peeled off and implied to have gain bone density while Mikasa and Armin have to cut off their tails in order for their legs to grow.
- I Didn't Mean to Turn You On:
- Levi gets very frustrated when Eren chooses to sleep with him for warmth while naked.
- Eren sings a love song which causes Levi to go crazed with lust because he wasn't sure it would work.
- I Will Find You: Mikasa and Armin decide to leave Superior Sea and become human in order to find Eren.
- Instant Expert: Averted, when Eren gains his legs it takes a month on physical therapy to walk. Played straight as he learns how to swim with legs in two days.
- Innocent Fanservice Guy: Eren would often strip naked when alone in warmer weather if Levi or Hanji weren't watching him. Justified he's a mermaid and he never wore clothes at until he became fully human.
- In-Series Nickname: Hanji constantly refers Eren as the Mermaid Princess or just Princess.
- Interspecies Romance: Between Levi, a human soldier and Eren, a mermaid
- Island Base: Levi and Hanji live on one given to them by Queen Historia as both a reward for their services and to act as an R&D department for the crown.
- Late-Arrival Spoiler: This fic assumes that the reader has read the manga and know that Krista's name is actually Historia and is actually nobility and that Titans were once people.
- Last of Her Kind: Mikasa is/was the last mermaid with tentacles, Ymir was the last harpy before she became human
- Mage in Manhattan: A mermaid gets stuck in the human world with no way of getting back home.
- Maiden Name Debate: Levi takes Eren's surname when they get married.
- The Maze: In the world of the fanfic, wedding ceremonies involve entering a maze in order to find your betrothed, and consummating the marriage when you meet, before leaving together.
- Meaningful Rename: Levi becomes Levi Yeager when he and Eren decide to get married.
- Moment Killer: Eren himself kills the moment by pushing Levi into the ocean and then he hides in seaweed after Levi become too forward for his liking.
- Open Secret: Levi and Hanji do not bother keeping the fact that Eren was a former mermaid, informing their comrades not in the know.
- Only One Name:
- Justified as in story, surnames are a sign of importance and influence. As a war hero, Levi and Ymir were strongly encourage to adapt surnames, only to refuse.
- When Levi sends Erwin a letter signed with Levi Yeager, Erwin and Petra take it as a marriage announcement
- Our Mermaids Are Different: at first Eren and his village appears to be the standard half-human, half-fish mermaid and Mikasa is an octopus based mermaid but the former are escaped genetic experiments that were originally human and the latter were a branch that evolved within the sea. Mikasa's people were killed because of this and both variations cannot procreate with each other.
- Our Monsters Are Different: Ymir was a harpy and Sasha's village had werewolves, werebears and a titan.
- Painful Transformation: The transformation into human is not a pleasant process.
- Questionable Consent: Sure, Eren and Levi seem to mutually in love but how consensual can it be since Eren is only fifteen while Levi is in his mid-twenties, Eren has no way of getting home and depends on Levi for food, shelter and guidance. This does get addressed before Eren and Levi get married as Levi starts doubting Eren's feelings as he realizes that he trapped Eren on the island.
- Required Secondary Powers: Eren can see better in the dark and has very good upper body strength
- Retired Badass: Levi at the beginning of the fic.
- Rescue Romance: The start of Eren and Levi's relationship began when Eren saving him from drowning in a storm when his boat capsized.
- Sexy Shirt Switch: Eren takes to wearing Levi's mantle for warmth.
- Sorry That I'm Dying: Eren apologizes to Levi before he attempts to leave, trying to cover up his own death by saying he's returning home.
- Schizo Tech: They are in a medieval time period but have DNA scanners, the 3DM has just been invented and genetic engineering and plane flight are considered lost technologies.
- Sirens Are Mermaids: Eren has the beautiful, compelling voice of a siren. Which virtually entrances anyone who hears it.
- Superhuman Trafficking: General Dot Pixis attempts to kidnap Eren because he's a merboy, although Eren and Levi quickly put a stop to it.
- They Call Me MISTER Tibbs!: When Eren and Levi first meet the latter gets annoyed that the former addreses him without any honorifics and pinches his face until he calls Levi either "Corporal" or "Mr. Levi." This worked too well, that even after their Relationship Upgrade Levi has to coax Eren into calling him by his name.
- Universally Beloved Leader: Queen Historia is beloved by the people for overthrowing the decadent nobility and the former king and for massively improving the living conditions of the kingdom and bringing it to a modern age. She is sometimes referred to as a Goddess of Victory.
- Unperson: The elders of Superior Sea made everyone pretend that Eren, Reiner and Berholdt never existed when they didn't return.
- Whole-Plot Reference: It is noted that Eren would have made a good soldier if he was born human.
- Wound That Will Not Heal: Eren's tail is wounded by boat debri when he rescued Levi and didn't heal for a period of time. Deconstructed as the wound gets infected and Eren's physical condition declined until he gets deathly ill.
- Yandere: Levi likes the idea that he can decide whether when or how Eren lives or dies.
- You Can't Go Home Again: Eren is not sure if he even could go back to the superior sea
- Your Normal Is Our Taboo: Eren is completely horrified when Erwin kisses him on the hand because Eren is already engaged by that time.
