Voltron: Legendary Defender/Fandom Specific Plot

• A Species Swap. The most popular are Galra!Keith, who is usually Axca's brother, and Altean!Lance, who is usually Allura's cousin.
• When Keith finds out that he's half-Galra, he's subject to massive amounts of Fantastic Racism from the team who now consider him worse than Zarkon. Many of these fics involve Keith being poisoned almost to death by planets who somehow know his secret right away, and none of the team even considering that this might be a factor among certain Galra-hating species. Why yes, this is very common in Shiro/Keith fics.
• Post-Naxzela fics dealing with the fallout from Keith's attempted Heroic Sacrifice. This is especially popular for the rare Keith/Matt Holt pairing due to Matt's horrified reaction when Keith announced he would try to ram the living bomb planet with his own ship, but Shiro/Keith had its own share of fics in this vein as well.
• A lot of post-series fic has Lance "moving on" from Allura after she ascends to godhood and falling in love with Keith, who has inexplicably been pining for him from the sidelines the whole time. Pidge is another popular choice, though.
• Many AUs of the final episode have Allura surviving; either Honerva makes the reality-mending sacrifice on her own, Lotor is still alive but gives up his very existence to both flip the bird to Honerva and atone for his poor choices, or the Lions sacrifice themselves.
• Despite it being shown that Alfor only built five Lions, there's suddenly a sixth Paladin, usually orange, white, or pink. A common set up for Crossovers.
• Allura becoming the new Black Paladin after Shiro's disappearance is fairly popular.
• After the reveal of Adam as Shiro's former boyfriend in season 7, several fics popped up where the pair pretty much adopted Keith as their "son." This was most common in Klance fics.
  • Several pre-Kerberos Sheith fanwork pieces have Shiro cheating on Adam with a teenaged Keith.
• "Krolia adopts Acxa" fics became popular after season 7, with Acxa joining the Blade of Marmora. Though the latter eventually became canon per Keith's ending in the epilogue.
• Sheith fics where Curtis was an Arranged Marriage or Shiro only hooked up with him because he was too afraid to tell Keith he loved him. Either way, Shiro regrets it and goes on an epic quest to confess his love to Keith, who's been waiting patiently in the wings for him all this time. Curtis' feelings are never treated seriously, and near every single time he's treated as a nuisance or as an asshole for standing between Keith and Shiro's True Love.
  • Other fanworks make Shiro cheat on Curtis with Keith, and the readers are supposed to side with them and not with Curtis alias the person cheated on.
• Alpha/Beta/Omega fics, usually featuring Omega Keith getting pregnant by whoever the author pleases. Usually Shiro.
• Pretty much all Keith/Pidge pregnancy fics have Pidge turn into a whiny basket case during and after the pregnancy while Keith plays super-dad and acts as her comfort dispenser. A dramatic difficult birth tends to be par for the course, complete with screaming and Keith Mangsting about how scared he is for his suddenly-fragile babymama.
• Shiro being a Sex Slave during his time in Galra captivity, usually "owned" by Sendak. There's a more or less even split between fics that focus on Shiro's frame of mind as he's subjected to the abuse and violation, and the ones focusing on his healing process afterwards.
• Kosmo has puppies (generally via impregnating the Holts' lady dog, Baebae) and the puppies can teleport. Though this one shows up just as often in art or headcanon threads as it does in fic.