He might face opposition from his own pure - blood community. Since Hermione is a Muggle - born, saving her could be seen as going against their traditional values. So he could be ostracized or face threats from some of the more extreme pure - blood families.
On the other hand, Lucius could also gain some unexpected allies. There may be other wizards and witches who secretly oppose abuse and discrimination, and his act of saving Hermione could make him a hero in their eyes. This could lead to new friendships or alliances that he didn't anticipate.
The Ministry of Magic's reaction could be mixed. They might be grateful that he has stopped an abuse situation, but at the same time be suspicious of his motives. After all, Lucius has a bit of a shady past. So they could keep a close eye on him, which might limit his freedom and actions in the wizarding world.
One consequence could be that it creates a rift between Ron and Hermione. Hermione might be grateful to Lucius, which could make Ron jealous or angry. This could lead to a strain in their relationship, and they might have to work through their feelings about Lucius' interference.
One consequence could be that he gains an unexpected ally in Draco. Draco might feel indebted to Harry and start to change his views towards him, which could lead to some interesting interactions between them in the future. This could also cause some tension among their respective groups of friends.
She might face some magical backlash. Saving someone from the veil could be against the natural laws of magic in the fanfiction world, so she could experience some physical or mental exhaustion as a result.
One consequence could be that Bellatrix becomes enraged and sets out to hunt Fred down. This would put Fred in constant danger as Bellatrix is a very powerful and vengeful witch.
Well, perhaps he uses his influence in the wizarding world. Maybe he has some connections or knowledge that allows him to intervene and get Hermione out of the abusive situation. For example, he could use his status among the pure - blood families to put pressure on the abusers.
One consequence could be a change in the public's perception of Hermione. Some might see her as a hero for standing up against an unjust imprisonment, while others might view her actions as traitorous, especially if they believe Draco was truly guilty. This could create a divide among the wizarding community.
In this scenario, it could also lead to a major shift in the relationships within the fanfiction. Hermione might feel betrayed if Draco doesn't stand up to his father. And Draco could be forced to make a difficult choice between his family's expectations and his feelings for Hermione. Lucius's interference could also bring in other elements of the wizarding world, like the Ministry or other pure - blood families getting involved depending on how the situation unfolds.
She might face suspicion from her friends. Since Thorfinn Rowle could be associated with the dark side, her friends might not understand why she saved him. They could question her judgment and worry that she was getting involved in something dangerous or morally ambiguous.
She could face isolation within the Hogwarts community. The students might gossip about her newfound relationship with Lucius. Hermione may also become more involved in the darker aspects of the wizarding world if Lucius leads her that way. Her academic focus could shift as she gets caught up in the drama of this new relationship. Moreover, she may end up regretting leaving Draco if she later realizes that Lucius was just using her, and this could lead to a lot of emotional turmoil for her.
One consequence could be that Hermione becomes isolated from her original friends. Since she only trusts Lucius and Draco, her Gryffindor friends might not understand her actions and distance themselves from her.