Hey.

Duality of HJP: is a powerful Harry story that largely takes place outside Hogwarts and Britain as a whole. We'll get there, though. Harry will be what Tom, Dumbledore, and Gellert were at his various ages. A lot of the things he'll do was done by them unless I mention otherwise. I'm undecided on the pairing, but it won't be slash.

A few points:

Languages: Harry's literacy in multiple languages isn't unique to him. Barty Crouch Sr. and Dumbledore can canonically do it. In this universe, a lot of people can do it. Dumbledore, Barty, and a few others can speak fifteen plus and that's a unique ability.

Size: each magical population (creatures included) is much larger than in canon. This will be the case in any other stories I write.

Curriculum: Each school has a different one, so Harry and co will learn different spells at different times. I.e. the Summoning Charm is a first year spell at Durmstrang, human transfiguration will be a year earlier while things like vanishing and boggarts will be learned later.

OC Characters: there will be a lot of them, but most won't be heavily featured. A few of the characters are canon names though...

Potters:

Henry Porter: canonically Harry’s great-grandfather from Potter Family article on Pottermore. Sat on the Wizemgamot around World War I and publicly disagreed with the Minister for being against wizards aiding muggles.

Fleamont/Euphemia: James’ parents, who died of Dragon Pox right before Harry was born. Fleamont was a rich potion-maker who created Sleekeazy’s Hair Potion.

Charlus/Dorea: mentioned on the Black Family tree. They have one son who’ve I named Taurus.

Iolanthe Peverell: granddaughter of Ignotus. She married Hardwin Potter, who was the firstborn of the original Potter and Harry is his direct descendant.

Blacks

Arcturus/Melania: Black family tree. Sirius’ paternal grandparents.

Lucretia: Black family tree and Sirius’ paternal aunt. Married Molly Weasley’s favorite uncle, Ignatius.

Pollux: Black family tree. Sirius’ maternal grandparents.

Druella/Cygnus: Black family tree. The three Black sisters’ parents.

Callidora: Black family tree. Possibly Neville's great-grandmother. Definitely Ron’s Great Aunt.

Lysandra: Black family tree. Ron’s great-grandmother.

Order of the Phoenix:

Emmeline Vance: A member of the Advanced Guard at the beginning of OOtP. She’s dead by the beginning of HBP.

Edgar Bones: died with his parents and family during the first war.

Fabian/Gideon: killed by a group of Death Eaters led by Antonin Dolohov in the first war.

Marlene McKinnon: killed by a group led by Travers in the first war.

Ministry of Magic:

Gawain Robards: becomes Head of the Aurora office under Scrimgeour regime.

Williamson: the Auror who sees Voldemort at the end of OotP.

Croaker: mentioned in GoF along with Bode.

Hogwarts:

Eddie Carmichael: Ravenclaw mentioned in OotP. Swore a potion helped him get 10 Outstanding on his OWLs. A year ahead of Harry.

Cassius Warrington: Slytherin a year above Harry. Is a chaser, places his name on the goblet, and was on the Inquisitorial Squad.

Miles Bletchley: Slytherin Keeper mentioned in PS.

Roger Davies: Ravenclaw chaser, who takes Fleur to the Yule Ball.

Pucey: Slytherin Chaser in CoS at least.

Graham Montague: Slytherin Chaser, who Fred and George pushed in the vanishing cabinet.

Melinda Bobbin: member of the Slug Club. Her family owned a chain of apothecaries.

Durmstrang

Rolf Scamander: canonically Luna's husband and Newt Scamander's grandson.

Mafalda Prewett: was supposed to be a Slytherin first year in GoF.

Astoria Greengrass: canonically Draco Malfoy's wife.

Miscellaneous

Adalbert Waffling: one of Dumbledore’s mentors. Mentioned in his obituary.

Arsenius Jigger: author of Magical Drafts and Potions

Damocles Belby: inventor of the Wolfsbane.