Change the stakes, go full AU.

The prophecy is made a lot earlier, but only Dumbledore hears it.

Voldemort kills Dumbledore, takes possession of all Hallows. He takes over Wizarding Britain, and Harry Potter is born into a very different world. Similar to some of the BolshevikMuppet AUs or Bobika's AU.

Dumbledore is dead, so he can't be Harry's mysterious old man mentor.

However, Lily and James are alive, and HP grows up with magic. His parents and their friends can be good teachers, but none of them have developed an affinity with magic to the degree with which Dumbledore had. And it's not like everyone is alive and Harry can just hop over to Moody for defense training or Auntie Minnie for help with transfiguring petunias into parakeets. Harry needs to get to that level if he is to have a chance to defeat Voldemort, but he's gotta figure it out on his own in the end.

Now why would Harry want to go after Voldemort? He was born into this weird postwar state, and the Order is still kicking about, resisting. So, Harry doesn't go to Hogwarts, and when he's old enough, circumstances drag him into the war, much to his parents' dismay.

Since neither Harry nor Voldemort are aware of the prophecy, there's no direct reason for them to ever confront each other, but this Voldemort is an oppressive force in every conceivable sense. Harry grows up knowing that he could've lived in a happier world, where he'd have gone to Hogwarts, pulled pranks, avoided Puddifoots and played Quidditch.

Then it gets personal when Harry realises that Voldemort has the cloak, Harry's rightful inheritance or at the very least, his father's. While Voldemort still has no reason to come after Harry directly, he still sees the Order as a threat, and inevitably, Harry suffers more direct losses because of Voldemort, which increases his desire to eliminate him.

This works for me because it eliminates a lot of ab initio training montage and children things, meaning we can skip straight to the good stuff. The story can begin with an adult Harry who's been around war and magic all his life.

And maybe it's hard to hate canon!Voldemort because he's ultimately impotent. He tries so hard, and he's meant to be a genius, even handsome and charismatic, but he gets stumped by a baby of all things, and then gets the Scooby Doo villain treatment a few times, and Harry Potter is Jesus. If anything, it's easier to sympathise with Voldemort as some kind of anti-hero who will stop at nothing to preserve his immortality and power/control, even murdering a baby.

So, maybe it's easier to hate a Voldemort who's already won and is actively impeding on Harry's well-being and freedom, as opposed to Mr. Tom and his bait-n-switch trophy cauldron act.

 

I'd go for more showing more of the impact of Voldemort and the Death Eaters/his ideology on the wizarding world. In the books all we really ever saw of it for most of the story is Draco screaming Mudblood all the time like an angry 12 year old X-Box Live.

I expect we would have a lot more hate for the Death Eaters if we saw their impact beyond just being told "Oh yeah, they're bad guys and racists." Tying things back to Draco, maybe have someone point out that he's going around racial slurs and nobody cares, and McGonagall seethingly growl that the last time she disciplined a pureblood for using that sort of language, it got her censured by the Board of Directors for "punishing a student who did nothing wrong." Or maybe have Snape coldly tell Hermoine she needs to get used to being called a Mudblood, because she's going to be hearing that word a lot.

I could also see a lot of potential with the various Diagon Alley scenes. During his first shopping trip, have Harry see one or two shops with "No Mudbloods allowed" signs up in the windows. Maybe have someone innocently comment on how Harry's remarkably "articulate" (or whatever good term would apply) for having been raised by Muggles. Maybe have Harry encounter one or two bits of racism from people assuming he's Muggleborn, but then shifting gears once they find out he's Harry Potter.

This all gets stepped up after Voldemort's return, maybe have one of the shops get blown up by Death Eaters, and afterwards we see a lot of businesses refusing to serve Harry and/or Hermoine because they don't want to risk making themselves targets. For extra impact make it someone who's always seemed nice and friendly to the group before, but now quietly pleads for them to leave because Death Eaters target anyone who sells to Muggleborns, and they've got a family. It's easy enough to hate the racists and Death Eaters, but it adds a new level when good people have to go along with them out of fear.

And, of course, things aren't any safer at Hogwarts. Make the climate of fear that started in Book 5 get even worse in Book 6. Show the world getting darker and darker with Voldemort's return and spreading influence. Maybe something like Muggleborn students suffering suspicious accidents whenever no witnesses are around, and it threatening to rip the school apart as the Gryffindors immediately blame the Slytherins (with Harry likely suspecting it's something Malfoy's involved in). If we want to set up Malfoy's redemption, have him being more-or-less pressured into going along with the attacks, but just not comfortable with the ugly reality of everything his family taught him to believe in.

The problem in canon is that Voldemort remains a distant looming threat, but his presence in the story is rarely felt before the big dramatic climax. Compare that to Sirius Black or Umbridge, whose presence was a constant thing in Prisoner of Azkaban and Order of the Phoenix. Voldemort isn't so much a dark looming presence destroying everything joyful in Harry's life as the guy who shows up in the last 100 pages to give us an exciting climax.

 

I probably agree with @Chengar Qordath most here with how to make Voldemort scary and hateable: make him the natural outgrowth of everything perverse and systemically wrong about the wizarding world, but the truly ugly step is show how inevitable he is. Not only is he powerful, he's two or three steps ahead of you and he's looking to make this personal in ways only a true psychopath would... but not because he's focused on Harry as a particular threat, but because he's an obstruction that should be dealt with as completely as possible.

For example, I've been rereading Renegade Cause and Criminal Limit (for... reasons) and while certain scenes like the infamous waffle showed a Voldemort who had a flair for the dramatic and sadistic, what spring to mind more for making you hate Voldemort are where he just doesn't abide by any rules of decency in his merciless exploitation of established systems and moral codes, and he's powerful enough to get away with it. He goes after your friends and family. He uses his Death Eaters for as long as he needs to... and then leaves them hanging out to dry (everything that happened to the Malfoys in that story is a prime testament). He turns partners against each other, and he cultivates such a noxious air of distrust that paranoia reigns supreme.

But the thematic roots come in someone looking to isolate, abuse, and break people with what they cherish the most - and for most that's friends and family. That's why possession is such a horrifying weapon he uses time and time again across that story, not just in the trauma he's going to wreak on the possessed, but also in the aftermath in social and emotional damage: he's ruining your life not just in what he's forcing you to do, but in how to the majority of eyes, you were the one who did it, because he knows society at large will do half his job for him.

And in the case of Cassane...

Spoiler

shit, possession wasn't even needed there so much as offer a desperate, emotionally ruined man everything he could want, a delusion of hope... only to never really deliver. That's the undercurrent that ran through for Dolohov as well.

So yeah, if you want Voldemort to be hateable, make him inevitable, and willing to ruin or turn everything you love against you, where even if you might win, you still lose... and have to keep fighting anyway.

 

Change his appearance. Instead of the inhuman and impossible to relate to snake lich, have Voldemort look like a grown-up version of the Tom Riddle in the diary - a charming, prettyboy asshole who abuses the trust, loyalty and goodwill of everyone around him. There were plenty of instances of Voldemort using people and betraying their trust in the books, but we only ever saw the aftermath of it - Ginny, Hepzibah Smith, Slughorn, Helena Ravenclaw, and so on. We should get to see the whole process, maybe even going further than what happened with those four, and see him swaying good-natured individuals into a death spiral of ever greater depravities. That would give us the kind of intimate and personal understanding of the harm he causes that was only passingly alluded to most of the time in the books.

 

I don't think that I had any strong emotions towards Voldemort when I was younger, but near the end of the HBP, when Draco is trying to psyche himself up to kill Dumbledore, and he reveals that if he doesn't do it his life and the lives of his parents are forfeit, all because of Lucius's 'mistakes' at the Ministry I began to feel a bit of disgust towards him. If you take away the disdain most people have towards Malfoy because of his actions in the previous books, and put this scene into context, Voldemort is forcing a 16 year old boy to become a murderer. I think that playing up this disdain that Voldemort has for human life, and the games he plays with his followers, but directing them towards characters like the Weasleys, who we have actual affection for, would be a very effective tactic. For instance, Voldemort could take Mrs Weasley captive and force Arthur or their kids to kill for him or take the mark.

 

I mean, I think he's pretty easy to hate as is, no fandom spice up required. Dude is literally Wizard Hitler but unlike Hitler he actually gets his hands dirty. Just showcase the violence, cruelty, and sadism more than the books did, and you have a very dislikable character.

 

I hate it when stories like that get far, FAR more kudos, comments, and bookmarks than the average well-written fic out there.

 

If you want kudos and comments on AO3, write for the audience there is rather than the audience you wish there was. Alternatively, don't post on AO3 unless you're writing weird smut, given that thats pretty much all a majority of the readers there seem to want.