The fanfic might show Harry being trained by the three Death Eaters in a way that challenges his beliefs and values. He could be exposed to new forms of magic that he's never seen before, which are probably dark in nature. However, his experiences with his friends at Hogwarts and his own sense of right and wrong would constantly be at war with what he's being taught. There could also be a power struggle between Harry and the Death Eaters during the training process, as they try to control him and he tries to resist in his own clever ways.
Well, in a fanfic like this, it could be that the three Death Eaters have some ulterior motive for training Harry. They might think they can turn him to their side and use his powers for their evil plans. Harry, on the other hand, could be biding his time, learning their secrets so he can later use it against them. For example, he could be learning about their hideouts or how they communicate, all while pretending to go along with their training.
Maybe the Death Eaters save Harry, but then they try to use him as a bargaining chip. They think they can trade Harry's safety for something they want, like amnesty or a powerful magical artifact. However, things don't go as planned and they end up having to truly protect him.
The redemption arc of some Death Eaters can also be a plot device. In some fanfictions, Harry tries to save some of the Death Eaters who he believes can be redeemed. This adds a layer of complexity to the story as he has to balance his desire for revenge with his moral compass. He may end up sparing some Death Eaters who then help him in his fight against the more hardcore ones.
A possible motive could be self - preservation. If they believe that Voldemort's downfall is inevitable and that by saving Harry, they can gain some form of leniency from the side that opposes Voldemort. They might think that Harry has enough influence to spare their lives if they help him.
Well, if we look at 'Harry Joins Death Eaters Fanfic', it could lead to a whole new set of storylines. Harry might be lured in by the power the Death Eaters seem to have. He could start using dark magic, and his moral compass would be all messed up. Maybe he'd be used by Voldemort to infiltrate the Order of the Phoenix from the inside. It would be a very different Harry, one who has lost his way and is now on the side of evil.
There's no way to know for sure without reading the fanfic. It could be some well - known Death Eaters like Bellatrix Lestrange, Lucius Malfoy, and Severus Snape (although Snape has a more complex relationship with Harry in the original story).
One idea could be that Daphne, who may be on the verge of being lured into the Death Eaters' ideology, is saved by Harry. Harry discovers that Daphne has some family pressure to side with the Death Eaters. He tries to show her the true nature of Voldemort and his followers. They form an unlikely alliance and work together to expose some of the Death Eaters' secrets within Hogwarts.
Well, perhaps in this fanfiction, there's a big misunderstanding. Harry might think that by infiltrating the Death Eaters as one of them, he can actually bring them down from the inside. So he pretends to join them, but things get out of hand as he has to constantly prove his loyalty to the dark side, which is really difficult for him.
Well, one possibility could be that he is forced to join them under some kind of dark magic threat. Maybe Voldemort has found a way to control his mind and he has no choice but to follow their orders. This would lead to a lot of internal conflict for Harry as he struggles with his own values.
Maybe he would be trained to be a super - powerful dark wizard. However, his natural good - heartedness, which he got from his parents, starts to shine through. This could lead to a conflict within the Death Eater community. He might be seen as a threat to their ideology and have to fight for his life against those who raised him.
The plot could be full of twists and turns. For example, the Death Eaters might be expecting Harry's attack and have their own counter - measures. But Harry outsmarts them and still manages to blow them up. There could also be moments where Harry is in danger but his quick thinking and powerful magic save the day and allow him to continue his assault on the Death Eaters.