DaoistewNoKO
There was no need to treat him so badly, even if they thought he was the incarnation of Voldemort. They could have simply asked for someone to check if Voldemort has taken over his body or was just in a certain area. Even if he was the incarnation of voldemort simply put him down and not torture him. Cause if you are willing to torture someone who looks like your child something is very wrong, way better to just kill them
Adding on to this If your child may be possessed or taken over by someone, most parents reactions would be to continue desperately checking to see if their child is in there. Not decide that he became the one how is thought to possess them. And as far as what’s going on in this story Dumbledor only suggested that it might be Voldemort possessing him. Not that it was a garunteed and such. Also as far as we are aware dumbledor did not cast magic on them to make them believe that, they themselves agreed with it and abused him on there own as Dumbledor didn’t tell them to abuse or treat the mc badly, it was they themselves who took that choice and did it.
Hindsight doesn't matter. Just because they know now they made a mistake doesn't absolve them of their actions. They may ask for forgiveness but they need to repent for their actions. Most of all, they need to put pressure on ol' Dumbles who was the cause of everything. His greater good disregards the individual, which caused the whole situation in the first place. In your story, he is worse then Voldy. At least Voldy knows and accepts that he is evil. Dumbles keeps marching on thinking he is doing the world a favor no matter how many people fall for HIS greater good.
I am not criticizing but just want to say in recent chapters it feel like mc just totally forgot about revenge and is acting far more like a kid than as a adult who got reincarnated and was planning to do something when he got system, just don’t take away his character and he should kinda start planning or fighting against dumbeldore for sure