What could be the most interesting plot in a 'Fairy Tail meets Game of Thrones' fanfiction?

Well, some might argue that Aegon Targaryen with his dragon in Game of Thrones would be very powerful. But if we consider Fairy Tail, Acnologia, the dragon king, would be extremely powerful. If he were to enter the Game of Thrones world, he could easily destroy entire armies and fortresses with his dragon powers.

One possible plot could be Sonic accidentally getting transported to the Fairy Tail world. He teams up with Natsu and they have a race to see who is faster. Along the way, they encounter a powerful dark wizard who has a device that can slow Sonic down. They must work together to defeat the wizard and Sonic finds a way back to his own world.

One popular crossover idea is the characters from Fairy Tail facing the political intrigue of Westeros like in Game of Thrones. For example, Natsu could find himself in the middle of a power struggle for the Iron Throne. Another is having the magic from Fairy Tail being introduced to the world of Game of Thrones, which would completely change the dynamics of battles and power plays. And some might imagine the guilds in Fairy Tail getting involved in the wars between the different houses in Westeros.

It could involve Erza facing challenges in the Edolas version of Fairy Tail. Maybe she has to deal with different versions of her friends or new magical threats specific to that realm.

A really cool plot twist could be that the magic in Fairy Tail is somehow connected to the sins in Seven Deadly Sins. So, when a Fairy Tail mage uses too much of a certain type of magic, it starts to manifest as one of the seven deadly sins. This could create a whole new set of challenges for the characters as they have to not only fight external enemies but also control their own inner 'sins' that are now linked to their magic.

One idea could be that the Fairy Tail guild travels to the Naruto world somehow. They could team up with the ninja to fight a common enemy like a powerful dark magic user who has also invaded the ninja world. Maybe Natsu's fire magic could be compared and combined with Sasuke's fire jutsu in some unique ways during battles.

One idea could be that Igneel appears in a time when Fairy Tail is facing an enemy they can't defeat. Igneel's power and wisdom help turn the tide. For example, he could teach Natsu some new and powerful dragon slaying magic that Natsu then uses to overpower the foe.

One interesting plot twist could be that Lucy discovers a hidden power within herself that is linked to End. Maybe she can control a part of End's power and use it to save the Fairy Tail guild from a great danger. For example, she might be able to use it to stop an ancient evil that is more powerful than any they've faced before.

Perhaps a character who was thought to be dead suddenly returns with new powers. For example, if Ned Stark came back as a warg, able to control animals and use that to his advantage in the power struggles of Westeros. It would completely change the dynamics as the other characters would have to deal with his unexpected resurrection and new abilities.

Natsu would be one of the most interesting. His fiery nature and his constant search for adventure would make his reactions to the real world really exciting. He might go around trying to find things that can give him the same thrill as fighting a powerful magic - using enemy in his world.