In this fanfiction, perhaps it starts with a strange prophecy related to Harry becoming a hollow as a baby. The wizarding world might be in chaos because they don't understand what this means for the future. As a baby - hollow, Harry could have some special powers or abilities that are unknown to normal wizards. His friends at Hogwarts later on might discover his true form gradually and help him to either reverse it or use it to fight against a new, greater evil in the wizarding world.
Another possibility is that the wizarding establishment itself could be the antagonist. They might be afraid of Harry's new form and try to isolate or even eliminate him. After all, a hollow - like Harry could be seen as a threat to the normal order of the wizarding world, and they might not want to take any chances, so they would oppose Harry at every turn.
In this fanfiction, perhaps Harry's hollow state gives him some unique powers that are different from his normal wizard abilities. For example, he could have enhanced speed or the ability to disappear in a different way. And Voldemort might sense this strange new power and be both intrigued and threatened by it.
Some dark wizards or witches who are looking for power might see Harry as a tool or a target. If they think they can harness the power of a hollow - Harry, they would try to capture him. This could lead to many battles and challenges for Harry as he grows up in this strange new form.
One possible plot could be that a powerful dark wizard, other than Voldemort, steals baby Harry for his own dark purposes. Maybe he wants to raise Harry to be his apprentice in the dark arts. He could take Harry to a hidden lair far away from the wizarding world, and as Harry grows up, he starts to suspect that his 'guardian' is not a good person.
Maybe it could be about Harry Potter being reborn as a Cybertronian baby and having to adapt to the unique culture and abilities of the Cybertronians. He might discover he has some special powers related to both his wizarding past and his new Cybertronian form.
Well, perhaps in this fanfiction, Harry Potter stumbles upon a baby while on one of his adventures. Maybe the baby has some sort of magical power that he has to protect from the dark forces. It could also be that the baby is related to an old prophecy and Harry has to figure out how to keep it safe and fulfill the prophecy at the same time.
It could imply a really strange and distorted version of Harry Potter's upbringing. Maybe the fanfiction twists the original story so much that the values and events that shaped Harry in the real series are completely warped. For example, his relationships with Dumbledore, Hermione, and Ron might be very different in this fanfiction - based scenario.
In such a fanfiction, Harry Potter as a Hollow might lose his sense of self and humanity. He could be driven by basic instincts rather than his usual moral compass. This would likely lead to a very different dynamic in the wizarding world as his friends would be faced with either trying to save him or having to oppose him.
It might be related to a secret society or a dark magic object. In the Harry Potter universe, there are often mysterious items with special powers. The hollow mask could be one such item, perhaps used for disguises or to access hidden places.
Well, perhaps the Yautja is on a hunt in its own world but gets caught in a magical portal that leads it to Hogwarts. The students are both scared and intrigued. Hermione starts researching about it, trying to find a way to send it back. Meanwhile, the Yautja sees the Death Eaters as worthy prey and starts stalking them. Harry has to convince the Yautja not to go on a full - out killing spree which might endanger innocent lives as well.