Luna might be initially cautious around Godzilla. Given her role as a princess in Equestria, she would likely try to assess if Godzilla is a threat. Godzilla, on the other hand, might be confused by the new environment. Eventually, Luna could use her magic to communicate with Godzilla, perhaps on a telepathic level. They would then start to understand each other's motives and find common ground, like protecting their respective homes from danger.
The interaction could be really complex. The ponies, being magical creatures, could try to use their spells to understand Godzilla's language or intentions. Godzilla, who is used to a world of destruction and chaos, might be confused by the colorful and peaceful world of Equestria. There could be a lot of misunderstandings at first. For example, when Godzilla roars, the ponies might think he's angry, but he could just be trying to communicate. And as they slowly start to understand each other, they could form an unlikely alliance. Maybe the ponies help Godzilla find his way home, and in return, Godzilla protects them from any future threats that might come from his world.
A plot could involve a group of villains from another world who want to capture both Godzilla and Luna to use their powers. They manage to transport Godzilla to Equestria. Luna, being the protector of the night, finds Godzilla and realizes that they need to escape and fight back. Along the way, they meet various other My Little Pony characters who help them in different ways. Eventually, they face the villains and with their combined strength and the help of their new friends, they defeat the villains and Godzilla returns to his own world, but not before a new friendship is formed between him and Luna.
The ponies' magic could play a big role in their interactions. If a dinosaur was about to attack, a unicorn pony could use a protection spell. The Jurassic World characters, especially the park rangers, might see the ponies as potential allies in controlling the dinosaurs. And the ponies could learn a lot about survival in a harsh environment from the humans.
The soldier might be a bit rough around the edges at first. He could be used to a more serious and tough environment. But the ponies, with their friendly and kind nature, would probably try to make him feel welcome. For example, Twilight Sparkle might offer to show him the library and share knowledge, while Pinkie Pie would throw a party to cheer him up.
Well, the ponies and Ice Age characters would interact based on their different strengths and personalities. The ponies, with their magic and unique abilities, could offer new solutions to the problems the Ice Age characters face. For example, Twilight Sparkle could use her magic to create warmth in the cold Ice Age environment. In return, the Ice Age characters could teach the ponies about survival in a tough, natural world. Manny's strength and leadership could inspire the ponies, and the ponies' sense of community and friendship could have a positive impact on the relationships between the Ice Age animals. They would likely have to overcome some initial misunderstandings due to their very different worlds and cultures, but in the end, form a strong bond through their shared adventures.
The interaction would be quite interesting. The Naruto characters, who are used to a world of battles and rivalries, would be introduced to the more harmonious world of the Crystalist ponies. Naruto himself would probably be very excited to learn about the different kinds of magic the ponies possess. He might try to incorporate some of it into his own fighting style. The ponies would be fascinated by Naruto's ability to use chakra. They would start to communicate through simple gestures at first, but as they get to know each other better, they would develop a more complex form of communication. There could be some comical moments, like Naruto trying to ride one of the ponies and falling off, or the ponies trying to use a kunai and failing miserably.
Pinkie Pie would be all over the Pokemon, throwing parties for them and making new friends easily. The more energetic Pokemon like Charmander or Cyndaquil would probably be drawn to her fun - loving nature. She would introduce them to all the fun things in Equestria like parties and games.
Well, a frequent theme is adaptation. Godzilla has to adapt to the bright and friendly world of the ponies, and the ponies have to adapt to the presence of a huge, potentially dangerous monster. Friendship is also a theme, although it might be a bit of a stretch considering Godzilla's nature. But some fanfictions try to show how the ponies' friendship could influence Godzilla. And there's the theme of power. Godzilla has his own kind of power, and the ponies have their magic, and fanfictions often play with how these powers interact.
Some characters might be amused. They could enjoy seeing how the fans see them and their world. For instance, Pinkie Pie would probably find the fun and wacky fanfictions really entertaining.
In fanfiction, the characters could also interact on an emotional level. Maybe Peter Parker (Spiderman) is feeling down and the ponies, with their positive and friendly nature, cheer him up. Or a pony could be in trouble and Spiderman comes to the rescue, and in the process, they form a bond. The ponies could teach Spiderman about the power of friendship, which is a central theme in My Little Pony, and Spiderman could teach them about courage and responsibility.