It's popular because it combines different beloved universes. Fans of both Harry Potter and another series get to see their favorite characters interact. For example, a crossover with 'Marvel' would let us see Harry Potter with the Avengers. It creates new and exciting storylines that we wouldn't get in the original works.
Well, if Harry got a howler from Voldemort, it might be filled with dark magic and menacing words to unnerve Harry. It could also be a ploy to throw him off his guard and disrupt his focus on fighting evil.
One idea could be that the characters from 'Got' somehow end up at Hogwarts. For example, Jon Snow could be a new student who is really good at Defense Against the Dark Arts because of his combat skills. He might struggle with the magical aspects at first but quickly adapt.
In fanfiction, if Harry Potter got Ginny pregnant, it could lead to a whole new set of adventures. They might have to face the challenges of starting a family while still dealing with the wizarding world's threats. It could also mean a shift in their relationship dynamics, from being a couple to becoming parents.
He would probably become extremely powerful. He could use the Infinity Stones' powers to defeat Voldemort in an instant. For example, the Power Stone could enhance his magic to an unimaginable level, and the Time Stone might allow him to go back and prevent bad things from happening in the wizarding world.
One great example could be a crossover with 'Lord of the Rings'. Imagine Harry Potter and his friends in Middle - earth, facing the dark forces there. Another is a crossover with 'Percy Jackson'. It would be interesting to see how the wizarding world and the demigod world interact. There's also the possibility of a crossover with 'Sherlock Holmes', where Holmes tries to solve the mysteries in the magical world of Harry Potter.
In a crossover, the dragons in 'Got' could be related to the magical creatures in 'Harry Potter'. Maybe they are a long - lost, more powerful version of a magical beast. Their fire - breathing ability could be enhanced by magic spells, and they could be used in battles against the Death Eaters or other dark forces. Daenerys could learn some magic from Hogwarts professors to better control her dragons.
The story could develop in a very different way. Harry might continue to live a normal Muggle life, completely unaware of his magical abilities. He would probably grow up thinking he was just an ordinary boy, going to a normal school and having normal friends.
In the fanfiction, it could be that Harry's aunt and uncle managed to intercept the letter before it got to Harry. They were so determined to keep Harry away from the wizarding world that they might have found a way to stop the owl or trick the postal system. They could have used some kind of Muggle - magic repelling charm they got hold of somehow. This would be a very interesting twist in the story as it shows how far they would go to keep Harry ordinary.
The plot would be much more complex. Harry could easily defeat Voldemort with the combined power of the Infinity Stones. So the main conflict of the original story would be resolved very quickly.