The portraits could offer him emotional support. Just seeing his parents' faces might give Harry the strength to face difficulties. For example, when he's feeling down or facing a tough decision, looking at the portraits could be like getting a warm hug from his parents, even if they're not physically there.
He would probably be overjoyed. Harry has always longed for a connection with his parents. Getting their portraits would be like getting a part of them back. He might just stand there, staring at the portraits with a big smile on his face, unable to take his eyes off them.
Hermione and Ron are usually quite common. Since they are Harry's best friends, they would be involved in the story when Harry's parents return. They might be curious about his parents, and also help Harry and his parents adjust to the current situation.
Well, it could be about him getting into trouble at Hogwarts. Maybe they scold him for sneaking out at night or getting involved in a dangerous adventure without permission.
In this fanfic, perhaps Harry stumbles upon the portraits while exploring a hidden part of Hogwarts. He might have an emotional moment as he sees his parents for the first time in this way, and the portraits could start interacting with him, sharing long - lost memories and advice.
Well, one possible plot development could be that when Harry gets his parents back, they have to quickly adapt to the modern wizarding world. His parents were from an earlier time, so things like new spells and magical devices might be quite a shock for them.
On a more magical level, reviving the dead is against the natural order of things in the wizarding world. This could attract unwanted attention from magical authorities or even dark forces. Some might see Harry's act as a dangerous precedent and try to either stop him or use his new - found power for their own evil purposes.
In some fanfictions, Harry might use extremely powerful and ancient magic. Maybe he discovers a long - lost spell during his adventures that has the power to reverse death. For example, he could find a spell hidden in a forgotten corner of the Hogwarts library that was created by a powerful wizard in the past but was deemed too dangerous to be used.