Harry Potter meets Terminator.

Part 1.

Everything happens as in the books until the seventh. Without going into details, the war is a long longer and involves the whole world. Harry becomes a legend similar to John Connor, helping Muggles fight the Dark Lord. While both sides are more or less evenly numbered in terms of Wizards and Witches, Voldemort is forced to make an army of magical golems to fight non-magical people who given magical weapons can be dangerous.

In his spare time the Dark Lord researches different ways to finally kill his enemy and finally creates a spell that allows him to change the past before the Prophecy was made. A catch is that it only allows him to send an information. Once it's done the future ceases to exist and the new timeline takes it place. The Dark Lord finds a way around information limit which is to send a spell that creates a powerful golem with an instruction of what to do and a full knowledge of future for past-Voldemort. Only problem is that he is unable to perform the necessary spell alone and he chooses the worst person to help him - Snape.

The traitorous spy managed to not get discovered until now, waiting for an opportunity like this one. He partially hijacks the spell and instead of knowledge of future for the golem, he sends his own memories to his past self, basically forcing him to become his future self by reliving his life in matter of second.

Without much of its information golem only tells past-Voldemort that Harry Potter will become his greatest enemy and that its here to kill him before he's even born. He almost succeeds, but at the last moment Lily is saved by Snape who explains the situation. She obviously doesn't believe him (there is a very strong theory published by Dumbledore that changing the past is impossible) until he mentions that she's pregnant which is something she only discovered few hours ago and didn't mention to anyone. She's still unsure, but decides to trust him.

In the end together they manage to destroy the golem, but Snape doesn't survive the battle. Lily tells his story to James and the rest, but nobody believes it and they think she became mad after the whole affair.

The big change is that there is no Prophecy and because of that Dumbledore is the one to vanquish the Dark Lord, if only temporary. But the Fate remembers what happened originally and it takes a lot more to completely rewrite the future. Because of that Harry and Voldemort are still destined to fight each other. Lily is aware of this fact.

After Harry is born, James concerned by his wife erratic behavior wants to take him from her and put her in St. Mungo's, but before he can do it, she escapes taking her son with her. They disappear for ~15 years.

Part 2.

In a new timeline the war happens again and once again Voldemort sends golem into the past. Since he was aware that he's capable of this feat, he managed to create the spell earlier and improved his magical weapon so it could be a lot harder to destroy than the one he met.

Harry too is aware of time traveling possibilities, but unfortunately he lacks Voldemort's talent to do it on his own. With a help from his friends he manages to create a different spell that will hijack the Dark Lord's and once again send someone's memories to the past.

In the past Lily basically became Sarah Connor from Terminator 2. Just as badass with addition of magic. Harry on the other hand isn't too happy with a life of constant running away from dangers real and imagined. After another of their arguments, he finally tells her that he thinks she's crazy and wants to go back to his father. His mother, completely heartbroken, allows it.

Even though James decided to divorce Lily after few years of her running away from him, he never stopped looking for his son and is happy that he returned. He immediately contacts Albus for help in enrolling Harry in Hogwarts so he could have even just a few years of normal (by Wizards' standards) childhood (teenagehood?).

That's all I got. I'm unsure who should be a time traveler send by Harry. He himself is a good option, especially when he can be used used to explore Lily's character even more. It would be a quite dramatic situation for her to see how her action and decision transformed her beloved son into what she though she wanted him to become. A coldblooded man prepared to do anything to ensure a survival of these he cares about.

 

I'd read it. But I am a bit iffy about the fact that nobody would believe her. Lily is established as an honest, supremely talented witch, who lives in a world where the impossible becomes possible every day. If the Lovegoods came this far before being institutionalized, I'm pretty sure Lily would escape that fate too. Maybe people thought Dark Wizards (Snape?) has messed with her mind?

 

James is less worried about what she's saying and more about what she may do with Harry. And for a good reason since she ended up kidnapping him to transform him into a soldier ready for an upcoming war. As for them not believing her, they actually don't believe Snape (they simply assume that a golem was a creation of current Voldemort and Severus was lying for some reason about the rest) and are worried that she does. They definitely can suspect that he somehow messed with her mind.

And I would find it really amusing to make Wizards very conservative in their beliefs. Sure, from Muggles' point of view magic proves that everything is possible, but from theirs there is nothing special about it and if something is said to be impossible (like changing the past) then they will find it extremely hard to believe it can be done.

 

The end of the XXI century. The wizardling population shrunk down to a single community. It's basically a reservation where the diminished population of wizards and magical creatures are allowed to live like they want. They don't know much about the rest of the world, believing (with the exception of several key individuals in the Ministry of Magic) that the wards protect them from Muggles.
Meanwhile the rest of the humanity colonized the outer solar system, created the advances spaceships to explore the stars... and had the misfortune to run into a hostile alien race. The Earth is forced to enter the war... and the wizard find, much to their horror, that their wards aren't as good as they think and they are forced to join the war against the foe much worse than all the Dark Lords combined.

 

Wizards vs Aliens is actually a pretty cool idea, but the rest of the idea irks me. The whole decimated Wizarding World thing has been done to death. I really want to see more fics where the situation is reversed. The muggles wipe each other out (biological warfare cause nukes are so 1960s) and the wizards come out of their secluded living space to find the Earth empty and theirs for the taking.

 

Harry Potter Nasuverse fusion, with HP elements subsumed into the Nasuverse, rather than vice versa. Prominent magical families from HPverse would exist in the fusion, such as the Malfoys, Blacks, Greengrasses, Notts, and so forth.

Hogwarts would serve as a select 7-year program in Edinburgh, Scotland, grooming promising young magi for induction into the Mages' Association at Clock Tower, accepting candidates at the age of 11. Albus Dumbledore would serve as the current Director of Hogwarts, along with Vice Director Minerva McGonagall.

Harry Potter would surprisingly end up as one of those candidates, as the last surviving member of very old Potter family, despite his ignorance of the Moonlit World. Potter's particular claim to fame is his status as the "Boy-Who-Lived," the lone survivor of an assault by the self-styled Dark Lord Voldemort, who mysteriously perished after killing James and Lily Potter and failing to kill Harry Potter.

(Voldemort had been a particularly brutal rogue magus who operated without care to the political niceties of Clock Tower and had no qualms taking down Enforcers, Clock Tower personnel, or the potential exposure of magecraft to the mundane world. His mastery of magecraft was immense, making him a fearsome opponent approaching if not matching the likes of Magicians like the older Kaleidoscope in combat. His exact goals were unclear, but he had attracted a number of followers, known as "Death Eaters" utterly devoted to him. Voldemort's true goal had been to attain the Third Magic, as he currently persisted off an incomplete path to it via the use of Horcruces, which left him less whole. He operated throughout the 70s, before his reign abruptly came to an end on October 31st, 1981)

The Association had considered placing Potter under a Sealing Designation to understand just how Potter had survived contact with such an incredibly powerful magus, but was persuaded otherwise by Dumbledore and his allies. Dumbledore had gained fame for his defeating the previous Dark Lord, Grindelwald, as well as being one of the few magi who could match Voldemort in combat. His political clout allowed him to come to a compromise with Clock Tower, to allow Harry instead to be inducted into Hogwarts, with his progress in magecraft carefully tracked.

While unconfirmed, Dumbledore believed that Voldemort was not quite dead and that it was only through a powerful ritual of sacrifice performed by Lily and James Potter that turned Voldemort into a wraith-like state. He placed young Potter under the care of his last surviving kin, utilizing the connection with his last surviving blood relatives to protect him both against any remaining Death Eaters as well as magi that might seek to use him as a subject of their research.

While his relatives had nominal knowledge of the Moonlit World, they had - somewhat justifiable, given their experience - a hatred of magi and Potter was raised completely bereft of magical knowledge. He would enter Hogwarts as an almost complete novice, putting him behind other students who would have entered with some knowledge of their family mysteries. He however found friends in Ronald Weasley, who hailed from one of the lesser magical families in Britain, and Hermione Granger, who also had been unaware of the Moonlit World prior to Hogwarts but had been selected for her innate magical potential.

Potter's first three years at Hogwarts would prove to involve more than just surviving schoolwork and wading through adolescent magi politics. In his first year, he would be put front and center of a plot to obtain the vaunted Philosopher's Stone, a Mystic Code at the pinnacle of Alchemy. The originator of the plot would be none other than Voldemort himself, acting through the guise of one of the instructors at Hogwarts and Harry would narrowly escape death. His second year would prove even more eventful than the last, with Harry coming into contact with Voldemort's memory in a surviving diary of his, facing off in a clash between himself and the young Voldemort along with his Basilisk familiar. His third year would not be as action-packed, although he would find out some shocking details on the circumstances of his parents' deaths, through none other than Sirius Black, Harry's godfather and a magus on the run from Association Enforcers for thirteen years.

Nothing however could compare to what happened in Harry Potter's fourth year, when he found three command seals on his left hand - marking him as a Master of the Fourth Holy Grail War in Fuyuki City, Japan...

 

You had me until this line. There's more to the Fate universe than just the HGW.

I'd also shy away from just copying HP plot into this fused universe - you've only posted the outlines, though, so maybe you'd be coloring them in differently, so to speak.

 

Harry Potter from a future ruled by Voldemort goes back in time to stop him. The only problem: said Voldemort comes with him.

 

It's probably already been done.

 

It has. They went back to Riddle's school years, and HP ended up a spirit without a body in a cruel role reversal.

Then HP possessed a boggart, regained a body capable of shape shifting and used it to taunt and play jokes on young Riddle. Can't remember the author or the story name.

 

I understand that Nasu is larger than Fate, but there are a few reasons why I thought the 4th HGW would be a nice way to introduce more familiar Nasu territory. First, KnK occurs as early as 1995, which would be HP's 5th year, but the 4th HGW takes place in 1994. (Leaving aside that KnK probably is an alternate universe from the universe where Fate and Tsukihime occur) So, the 4th HGW is probably the earliest opportunity for HP to run into some key and familiar Nasu characters, outside of the established side characters he might meet like the Queen of Clock Tower or perhaps other Clock Tower personnel. Outside of making things up, there simply isn't that much happening on the Nasu side of things canonically prior to 1994. (I suppose there would be Roa's possession of Ciel in 1992, but how is Harry going to be in a position to be involved in those events?)

In addition, logically speaking, Harry wouldn't really have an opportunity to meet much in the way of all the stuff going on in Japan (with F/Z, FSN, Tsukihime all occurring there) or much of the world abroad outside of Hogwarts, perhaps some of Clock Tower, and London in general. He's still a minor and in particular, a young magus in training at a facility aimed at instructing young magi, so it's not like he would have the opportunity for international travel. Being selected as a Master for the 4th Heaven's Feel I felt would provide the best plausible reason for why Harry would be allowed to and would be able to leave Britain to go to Japan, to get involved with the Nasuverse characters and events there.

In any case, I imagine the 4th HGW would serve as a major jumping off point, as it's unlikely to resemble canon HP even as a skeletal outline in the backlash of whatever the fallout of those events would be.

Also, as you suggest, one probably would fill in the details of Harry's first three years differently. For one, Hogwarts in this fused universe would probably be very, very different from canonical HP Hogwarts, if owing to the fact that most Magi are at best enlightened egoists and at worst amoral sociopaths in Nasuverse. Most of the students at Hogwarts would have been trained in their family magecraft for years prior to attending Hogwarts and would already have more than an inkling of the attitude expected of magi. In addition, people are less inclined to view Harry as a person to be revered to some extent in the Moonlit World and a more of a person as "Isn't it too bad we can't dissect this guy?" I also don't envision Hogwarts (if one uses that name) being all that old of an institution, unlike canon HP, given that Hogwarts is just a stepping stone to Clock Tower. In general, the atmosphere, feel, and day-to-day events at this Hogwarts should be very different as opposed to canon.

One could always scrap even the minimal canon rehash for Harry's first four years - that's not a big deal. It's just that I feel that the 4th Heaven's Feel is Harry's earliest and most plausible opportunity to interact with the Nasu characters that have actually been fleshed out.

EDIT: Also, looking over the Nasu timeline, we would have an excuse to have Bazett interact with Harry. She would be around Harry's age and could conceivably be a student at Hogwarts. (She was 23 during FSN, so should be no older than 13 during F/Z)

 

Harry meets his distant uncle and it changes his life.

Leisure Suit Harry: Take Out Your Wand!

 

Harry Potter and Ducktales Crossover featuring: Dumbledore as Scrooge McDuck, Harry as Huey, Ron as Louie, and Neville as Dewey. It's set in a world where Voldemort doesn't exist and the Potter, Weasley, and Longbottom parents take a group vacation/break from the kids for the summer when the kids are 10. Dumbledore, a close friend of all three families, agrees to babysit them in Hogwarts castle. The story is about their many highjinks and adventures as the trio explore Hogwarts Castle and the Forbidden Forest.

Harry Potter and Gravity Falls crossover. Harry and TwinOC are sent to Gruncle Aberforth's. They become fast friends with Hagrid and Tonks(?), and slowly begin to unravel the mystery surrounding their Gruncle Aberforth, the Forbidden Forest, and Hogwarts.

 

1. Then Mrs. Weasley is supposed to be Mrs. Beakly?
2. World without Voldemort? Just replace him with Magica de Spell.

 

1. I think McGonagall would make a better Mrs. Beakly. She tries to watch the kids while Dumbledore is away doing whatever it is he does.

2. This actually fits perfectly. The Beagle Boys are the Death Eaters.

 

I disagree. The Beagle Boys would obviously be the Inquisitorial Squad and Ma Beagle is Umbridge. And Flintheart Glomgold would be the obvious Grindelwald character.

Okay but the better question is which HP character is Launchpad McQuack? Or how about Fenton Crackshell A.K.A. Gizmoduck?

 

You're right about the Beagle Boys and Ma Beagle. Charlie could be Launchpad and Percy could be Fenton.

 

Then what about Gyro? The only person in the series who is tinkering with Muggle technology is Arthur.

 

Was thinking of a new spin on time travel and came up with something a bit quantum leapesque.

Harry Potter beats the dark lord, the back lash from all the pieces of his soul being killed and merged back at once causes Harry to travel throughout his life in three day spans, from birth to death and everything in between Harry is living his life on shuffle while trying to piece together what's happened and how he get himself back on track.

 

Yes, but the only person who invents things are the Weasley Twins