Timeskip 6 years
It had been six years since the escape of grindelwald and saints have become very active in these years yet with there connection they were completely elusive and Noone suspected saints as far as they know grindelwald is still in NURMENGARD
Pov Dumbledore
It had been 10 years since fall of voldemort and this year the savior will reappear in the wizarding world and I will train him to be selfless and understand love and he will be a perfect successor then I can retire with piece of mind
Knock! Knock! Knock!
Dumbledore: come in.
McGonagall: Albus please see what book of acceptance have to say
Dumbledore: come here and show me
Hermione granger, Orion Grindelwald, Harry Potter
Dumbledore: who is Orion Grindelwald
McGonagall: he lives very close to hogwarts and his postbox is at hogsmate village
Dumbledore: send the letter i will see him when he comes to school
Two days later
Diagon alley
Orion walked through the bustling streets of diagon alley he was here to make friends with draco malfoy as for Harry potter let Dumbledore have his savior anyway he will be going to slytherin
Outside madam molkins robe shop he met draco and both become friends very easily
Draco: father look I made a new friend
Lucius: Nice to meet you i am lucius malfoy
Orion: Nice to meet you too Mr malfoy I am orion Orion Grindelwald
Lucius: Grindelwald what is your relationship with Gellert Grindelwald
Orion: He is my father
Lucius: Being son of a dark lord your life wouldn't be easy
Orion: why do you think I went to hogwarts isn't it just because the greatest white wizard live here Do you really think the ministry can do anything to a student under Dumbledore protection
Hearing Orion's words Lucius realised that he was very smart and will most likely become third generation dark lord
Orion left after talking to Lucius with his charm he is sure that he will gain a lot of followers in slytherin combined with his sleeper agents planted in hogwarts by the end of this year he will have moe than three hundred followers
Even those with mideocre talent in magic have high talent in Combat due to alchemical enhancement