I'm sloooowly watching my way through the anime, but I'm much more familiar with the LA. Treats welcome and enabled!

DNWs: gore, animal cruelty, major character death (references to Bellmere's or Kuina's deaths okay), character bashing

Additional Tags:

• Alternate Universe - Daemons: I feel like daemon AUs are an excellent way of exploring a character's personality and upbringing: is the creature common to where they grew up (but not necessarily where they are now), or rarer? What does it signify to the character, and what does it imply to everyone else? I also really love same-gender daemons, and the many things that they could imply/represent; it kind of reminds me of the Ds, in a way.
• Alternate Universe - Different First Meeting - I love how first impressions shape character's relationships, and different first meetings are a great way to do it. What happens if these characters meet as children? As two mercenaries hired by the same person? In jail?
• Alternate Universe - Role Reversal - I'd love to see a backstory swap for various characters. What does young!Shanks think of Luffy and his cool Strawhat Pirate crew when they show up on his island? What happens if Bellemere and her new adoptees are the ones stranded with minimal resources, and Sanji's the one working for a dastardly pirate to protect the Baratie?
• Character Thinks No One is Coming to Save Them (Everyone is Coming to Save Them) - This is one of my ride-or-die tropes! Whether a version  of the incidents we see in-show (Arlong Park springs to mind) or a terrible misadventure of your own making, I am always all for a big damn heroes moment when someone thinks they're past redemption.
• Character Unexpectedly Turned Into a Child - This is another of my ride-or-die fanfic tropes because it so deftly combines (unwilling) backstory reveal, hurt/comfort, and lack of perspective from the now!child. Just a bunch of great tastes that taste great together.
• Hurt/Comfort - I love h/c so much! Favorite subtropes include: suffering hurt for someone else, unexpected comfort/comfort from an unexpected source, suffering stoically until the hurtee eventually breaks down, flip of typical hurtee/comfortee roles in a relatinship.
• Missing Scene - What happened when they were sailing along (or even on an island) that didn't get shown?
• Platonic Cuddling - Luffy is very physically affectionate, and that rubs off on everyone he meets.
• POV Outsider - I feel that Outsider POV allows for a lot of great worldbuilding (what does the outsider expect to see? why?), comedy (via misinterpretation of what's going on), and a real understanding that these people are Not Normal (said with love).
• Time Loop - I love a good time loop. What is the day/week/etc set to loop? How are they put into the loop, and what does it take to get out? How does the loop reset? What do the characters learn about themselves and each other in the loop, before breaking out of it with unexpected knowledge.
• Time Travel - I also really enjoy linear time travel. Whether change is possible or not, having characters experience an event from a new perspective (or just with future knowledge) lends an interesting POV to what's going on? How do people who haven't traveled react to the traveler?
• Time Travel Fix-It - And what happens when a character succeeds at fixing their past? How do they go about it, and are there knock-on effects they didn't intend?
• Whump - Because sometimes your faves need to suffer prettily. Combines well with h/c and everyone coming to the rescue.
• Worldbuilding - I am a huge worldbuilding fan, and One Piece has so many interesting possibilities! What does the history of this world look like? What does life look like logistically for different types of people, or islands in different places?

Akagami no Shanks | Red-Haired Shanks & Monkey D. Luffy

Alternate Universe - Daemons, Alternate Universe - Different First Meeting, Alternate Universe - Role Reversal, Character Thinks No One is Coming to Save Them (Everyone is Coming to Save Them), Character Unexpectedly Turned Into a Child, Hurt/Comfort, Missing Scene, Platonic Cuddling, POV Outsider, Time Loop, Time Travel, Time Travel Fix-It, Whump, Worldbuilding

I love Luffy and Shanks' relationship! Shanks hasn't seen Luffy in years, but their time together has a very clear influence on who Luffy is as a person: his understanding of pirate ideals, the casualness with which he levels massive strength, his fierce ties to friends, his tendency to be chill in situations he should probably be taking a little bit more seriously… I love it.

I'd love to see Luffy encounter Shanks again, now that they're captain to captain, or perhaps encounter him in a different way the first time - a prisoner of Garp's he helps escape? (Or a total roleswap, where baby!Shanks is overawed by adult!pirate!Luffy and friends - or even a time travel ouroboros version, where Shanks was influenced by Luffy and time travels back - on purpose or on accident - to influence him in turn.) How do they get along, now that they're closer to peers? What happens if there's a reversal of the seaking incident, where Luffy needs to save his mentor?

Coby & Monkey D. Luffy

Alternate Universe - Daemons, Alternate Universe - Different First Meeting, Alternate Universe - Role Reversal, Character Thinks No One is Coming to Save Them (Everyone is Coming to Save Them), Character Unexpectedly Turned Into a Child, Hurt/Comfort, Missing Scene, Platonic Cuddling, POV Outsider, Time Loop, Time Travel, Time Travel Fix-It, Whump, Worldbuilding

Coby and Luffy make such an interesting pair - hopeful pirate and would-be marine on a pirate ship, the one too calm about the situation and the one not calm enough, both about to get their understandings of the world tested. I'd love to see how their interactions evolve over time, either in an AU where Coby joins the Strawhats or as they face each other from opposite sides of the law. Do they come to understand the other (and their point of view) more over time, or less? (It could be fun to have an outside Marine POV wondering wtf is up with the two of them.)

Expanding on their time together in canon could also be really fun. What do they do when they're still on the ship together? What misadventures do they have getting to the Marine branch, and how could they end up having misadventures together once they got there?

I'd also really enjoy an AU where the sides are flipped - earnest new Marine Coby has to help get Luffy out of a corrupt base, or maybe Coby is an unintentional stowaway that allies himself with Alvida's unwilling cabin boy, Luffy.

Bell-mère & Nami & Nojiko, Nami & Nojiko

Alternate Universe - Daemons, Alternate Universe - Different First Meeting, Alternate Universe - Role Reversal, Character Thinks No One is Coming to Save Them (Everyone is Coming to Save Them), Character Unexpectedly Turned Into a Child, Hurt/Comfort, Missing Scene, Platonic Cuddling, POV Outsider, Time Loop, Time Travel, Time Travel Fix-It, Whump, Worldbuilding, Alternate Universe - Everyone Lives/Nobody Dies

I love what we got of Nami's family, and I'd love to see more. What's Nojiko's perspective on Nami turning to Arlong (at the time she makes her deal, in the years after, it all in retrospect once Arlong Park has been stormed)? How does their relationship change after season 1? Are they in contact at all while Nami is at sea?

I'd love to see Bellmere's relationship with her daughters in more detail, especially how it changes over time. For a nobody dies AU, I'd equally love an AU where Arlong never comes (...to Cocoyashi) and Nami becomes a cat burglar for other reasons to a version where Bellemere somehow survives Arlong coming (someone else dies instead? Taken prisoner? Narrowly survives but this needs to be kept secret?) and has to deal with Nami's choices afterwards. (Does Nami still decide to try to buy the village back with her mother still alive or does she try something else? Does Bellemere try to get some old Marine friends to help, and if so how does that go?)

For the time travel tags, I'd love to see a loop centered around Arlong's initial arrival (or maybe a varying-length one centered around the destruction of Arlong village), or Nami (and friends?) going back to that day, to change things or merely to observe them. Or maybe Nami isn't the one travelling at all; maybe Bellemere's in a loop that resets when her daughters die, or Nojiko is the one who flashes back/sideways and realizes why Nami joined the pirates (and now has to keep this a secret from everyone, including her sister).

Focus: Nami

Alternate Universe - Daemons, Alternate Universe - Different First Meeting, Alternate Universe - Role Reversal, Character Thinks No One is Coming to Save Them (Everyone is Coming to Save Them), Character Unexpectedly Turned Into a Child, Hurt/Comfort, Missing Scene, Platonic Cuddling, POV Outsider, Time Loop, Time Travel, Time Travel Fix-It, Whump, Worldbuilding, Heists

Nami is my favorite character in the LA; I really like her complicated motives, the way she's internally one step to the side of everyone else and how that builds to the dramatic reveal at the end. I'd love to see more of her time with the Arlong Pirates (or her thought process in proposing the deal) and more of her reaction in the aftermath of finally having them gone, and dealing with everything that's happened since.

For the de-aging tag in specific, I think her taciturn nature surrounding her backstory is great fodder for dramatic irony. Is she pre-Arlong, a kid with clear money issues but only the hangups around pirates that a devil-may-care Marine would impress upon her? Is she post-Arlong, with this new tattoo no one's seen before and amped up about something she's utterly unwilling to talk about.

For the time travel tags, I'd love to see a loop centered around Arlong's initial arrival (or maybe a varying-length one centered around the destruction of Arlong village), or Nami (and friends?) going back to that day, to change things or merely to observe them.

I also love Nami's thieving abilities, and I'd love to see a quick little heist she does on a crew (or Marine ship) that only realizes what hit them in retrospect.

Kuina & Roronoa Zoro

Alternate Universe - Daemons, Alternate Universe - Different First Meeting, Alternate Universe - Role Reversal, Character Thinks No One is Coming to Save Them (Everyone is Coming to Save Them), Character Unexpectedly Turned Into a Child, Hurt/Comfort, Missing Scene, Platonic Cuddling, POV Outsider, Time Loop, Time Travel, Time Travel Fix-It, Whump, Worldbuilding, Kuina (One Piece) Lives

This is a really impactful backstory scene, and I'd love to see more of Kuina and Zorro (either as children post-pact or in an AU where Kuina lives). How does their rivalry change over time; are they always the other's best competition, or do they mutually shift their sites on defeating/dealing with a specific person? How would Kuina fare in Zorro's shoes, were he the one to have the terrible childhood accident and she the one determined to keep their shared dream moving forward? As Kuina grows (and Zorro grows with her), does everything she's been told about swordswomen come true, or does she continue her dominance over the dojo (and come to the realization that she's internalized a bunch of nonsense)? If Kuina and Zorro both survive and continue as rivals, do they go out together, or do they separate and find each other again on the road of life?

For time-travel, I'd love an AU where Zorro saves Kuina (either traveling deliberately back to do it or getting lost in the timestream rather than on land); what knock-on effects happen because she survived? It could also be interesting to have her, rather than die from the accident, be catapulted forward in the timestream, and now seeking out her old friend (who's now significantly older than her and has also been putting her sword in his mouth).

Monkey D. Luffy & Nami & Roronoa Zoro & Usopp & Vinsmoke Sanji

Alternate Universe - Daemons, Alternate Universe - Different First Meeting, Alternate Universe - Role Reversal, Character Thinks No One is Coming to Save Them (Everyone is Coming to Save Them), Character Unexpectedly Turned Into a Child, Hurt/Comfort, Missing Scene, Platonic Cuddling, POV Outsider, Time Loop, Time Travel, Time Travel Fix-It, Whump, Worldbuilding

I love all the Strawhats, and I'd love to see them working together in whatever way (and at whatever time) you choose.

For a different first meeting or role reversal, I'd love a backstory swap of the Strawhats. Maybe Luffy is the one constantly declaring Shanks is coming back, or Sanji is the one fighting hard to save the Baratie from someone demanding tribute money from it. What changes about the Strawhats here, and what stays the same? I'd also be into an AU where they meet under different circumstances (all getting arrested at the Marine branch, or meeting in jail) or for a different purpose (forming a Marine squad, maybe?).

For getting turned into a child, I'd love the characters to get a chance to witness (and maybe compare notes on, if this is a running thing) each other's terrible backstories. If they're all made children at once, how do they work together against whatever made them that way?

For the time travel tags, I'd love to see the Strawhats interfering in each other's backstories (maybe not in the ways that they were intending to), or maybe all journeying together to a time and place they know nothing about.