The Trinity is afiction series written by a member of Beast's Lair forum called "Kieran."

The series is a retelling ofHarry Potter books with the titular character, alongside two other ones readers didn't really care about, being replaced by three characters (Emiya Shirou, now known as Shirou von Einzbern; Aozaki Takara, with her name unchanged; Jester, with his name becoming Galen Salvatore) from one of his earlier works. With Neville Longbottom being the one of whom the prophecy speaks after Harry Potter's death at the hands ofLord Voldemort, they are trying to fix what is left of the world they knew from books and movies,to have a place to live.

There are currently six books, out of seven planned, in order:

• Trinity I: The Stone
• Trinity II: The Chamber
• Trinity III: The Prisoner
• Trinity IV: The Tournament
• Trinity V: The Chosen
• Trinity VI: The Blood (currently being written)

There are also preludes to the story, known as "Legacies of Fate" (the first one), and "Truth and Consequences" (the second one).

• After the End: The reason they were able to appear inHarry Potter universe was Ilyasviel using her powers asthe Holy Grail to save them after their fight against Illyria.
• Berserk Button: Some characters have them, most notable ones being those:
  • Galen'sBerserk Button is seeing any of his friends, but especially Hermione or Takara, getting hurt.
  • Shirou'sBerserk Button is seeing Ilyasviel, or any of his family members, getting hurt.
• Black and White Insanity: Dumbledore's morality isone that only accepts white and black, which proves to be very problematic when two out of three wizards capable of stopping theBig Bad qualify asAnti Heroes, orByronic Heroes.
• Chekhov's Gun: Instead of letting Dumbledore destroy the philosopher's stone, the Trinity decided todeposit it in Hermione's Gringott's vault, with nobody outside of their group knowing they have it.
• Cursed with Awesome: From practical perspective, this is what Galen's lycanthropy is most of the time. But untilthey were able to give him improved Wolfsbane potion based on Snape's notes, physical suffering when he changed outweighed any potential bonuses.
  • Even more so in case ofLord Voldemort,who had gained partial lycanthropy after Galen's blood was used to revive him in the 4th book, resulting in the power of his unforgivable curses being increased. And since he had Snape with him, he didn't have to wait long for the cure.
• Dangerous Forbidden Technique:Horcruxes, obviously.
  • There is also Galen's Thunderbolt charm, which had almost become classified as the fourth unforgivable curse, and before he had perfected it,was very dangerous to the user.
• Darker and Edgier: The whole series is a tad darker than the original. Surprisingly, nobody had dieduntil the sixth volume.
• Father, I Want to Marry My Brother: Ilyasviel chose Shirou to be her "chosen" one. It had been a major problem for them in the fifth book, since they could not marry if there was no proof that they weren't related, and if that had not happened Ilyasviel would've died from the backslash of her Veela nature.
• Fix Fic: While the fiction itself had not been created to "fix" the events of the books, it does a great job at fixing variousPlot Holes in the original books.
• Foreshadowing: The identity of one of Shirou's parents had been foreshadowed byhis parseltongue ability.
• For Want of a Nail: Due to Ilyasviel's reality rewriting power, some facts had to be changed to accommodate the Trinity in theHarry Potter universe.
• In Spite of a Nail: Happens sometimes when the universe wants to shed their reality rewrite, and always causes things to turn much worse then they were.
• Luke, I Am Your Father: While it had not been stated clearly, it is implied, with evidence to back it, that Shirou's father isTom Riddle.
  • It had been revealed before that, whilst trying to prove he wasn't related by blood to the Einzberns,that his mother in this universe is Aozaki Touko, and that he isa few years older than his looks imply.
• Meaningful Rename:Shirou's full name changes to "Shirou Einzbern" when hemarries Ilyasviel.
• Not Blood Siblings: Ilyasviel and Shirou, of course.In fact, Shirou is Takara's cousin.
• Peggy Sue: A variation of this, the Trinity had prior knowledge ofHarry PotterCanon when they first arrived, and thus were able to use it to their advantage when this universe was still similar to the one they knew. It later bit them back, when the world diverged too greatly from the one they knew for them to do anything with this knowledge.
• Red Herring:The Triwizard Tournament cup in the 4th book. Following it allowedSnape to get blood necessary to resurrect Tom Riddle.
• Take a Third Option: In the third book, the Trinity had to either allow Peter Pettigrew to run away, or to kill him.They staged Sirius' escape, enabling him to kill Pettigrew in his human form, and thus both denying Riddle Pettigrew's help, and clearing Sirius' name.
• You Can't Go Home Again: None of the Trinity, norIlyasviel and Rin can go back to their home world. Because of that, they have to work hard to save the world if they want to have a place to live.
• You Have Outlived Your Usefulness:The most prominent example, though far from the only one, being Severus Snape.

• Work
• Harry Potter
• The Trinity
• Fanfic
• Fan Works
• Fan Works of the 2010s
• Fate/stay night/Fan Works
• Harry Potter/Fan Works
• Lunar Legend Tsukihime/Fan Works
• Mega Crossover