Socially, his status as a hero might change. Some might see him as weakened and no longer the invincible hero. This could lead to a shift in the wizarding community's perception of him, and he might have to work hard to regain his former standing.
He might have physical injuries that could slow him down in his training or his future battles. For instance, if he gets a deep wound on his leg, it would affect his mobility.
Hermione would immediately start researching ways to heal him. She'd pour over ancient books and consult with the most knowledgeable wizards to find a cure or at least a way to ease his pain.
His relationships could be affected. Hermione and Ron might have to take on more of a caretaker role, which could change the dynamic of their friendship. Also, he may face discrimination or pity from other students at Hogwarts, which could further isolate him. And in terms of romantic relationships, his self - esteem due to his crippled state might make him less likely to pursue someone like Ginny.
He could be captured and imprisoned. If Shield is a powerful and secretive organization, they might have their own prisons or ways of detaining people. Harry would lose his freedom and might not be able to continue his normal life or his fight against the real dark forces.
He might become more independent. Without the Dursleys, Harry would have to fend for himself. He could start to discover his true powers faster as he no longer has to hide his magic in the Dursley household. For example, he could practice magic freely and develop his skills more quickly.
He might feel a great sense of betrayal. Since Gryffindor was like his home in Hogwarts, being banned could make him question his identity. He could become more isolated and withdrawn at first. However, this could also lead to him finding new friends and allies from other houses or even outside of Hogwarts.
Well, if Harry gets rid of Snape, he might face backlash from the Slytherin house. Snape was a Slytherin and had his supporters there. They could make Harry's life difficult in various ways, like spreading rumors or trying to undermine his achievements. On the other hand, Harry might find new allies. Those who were secretly afraid of Snape but couldn't do anything might now side with Harry. But he also has to be careful not to let this new - found power go to his head, or he could end up making more enemies in the long run.
There could be some negative consequences too. Maybe the dragon had some kind of magical protection or was under the care of a powerful wizard or creature. Harry might then face the wrath of those who were protecting the dragon, leading to him having to go into hiding or facing dangerous challenges. Also, the act of killing a dragon, even in self - defense, might make some more sensitive wizards view him in a different, less favorable light.
One possible consequence is that the wizarding world might see Harry as a hero even more than before. After all, dementors are very dangerous creatures, and if he manages to destroy them, it's a huge accomplishment.
He might gain some extraordinary magical abilities. For example, he could be able to control time or have a deeper understanding of magic spells that were previously difficult for him.