Naruto would probably be in awe at first. He'd try to communicate with Mothra in his usual friendly and exuberant way. He might start by introducing himself and his village, just like he did with other summons. Then he'd try to understand Mothra's powers and how they can be used to help in battles or protect the village.
One possible plot could be that Naruto discovers a new and ancient summoning contract that allows him to summon Mothra. Mothra's appearance in the Naruto universe could cause chaos among the ninja villages as they've never seen such a creature. Naruto would have to learn how to control and work with Mothra to protect his village from new threats.
The exploration of new powers is also great. Since Mothra has her own set of powers, seeing how Naruto or other characters interact with and potentially gain new abilities related to Mothra is really exciting. It could lead to completely new story arcs and battles that we wouldn't see in the original Naruto series.
The interaction between them could be really interesting. Ilya, coming from her own magical background, would show Naruto some of her unique spells and abilities. Naruto, impressed by her magic, would then try to combine it with his ninja techniques. For example, he could use Ilya's teleportation spell in a new way during a fight. And they would also have some emotional exchanges, like when Naruto shares his story of losing Sasuke and Ilya comforts him with her own understanding of loss in her world.
There is also 'Mothra in the Hidden Leaf'. In this fanfiction, Mothra somehow ends up in the Hidden Leaf Village. Naruto befriends her, and they go through a series of events together, from helping villagers to facing off against some rogue ninjas who want to capture Mothra for their own evil plans.
Naruto, being his curious and friendly self, would probably be excited to meet the Final Fantasy summons. He might try to befriend them immediately. For example, if he summoned a Cactuar, he would likely be amused by its appearance and try to communicate with it. Sasuke, on the other hand, would be more cautious and see the summons as tools for power. He would study them to figure out how to use them to his advantage in his quest for revenge.
Regular Godzilla and Mothra stories usually focus on their battles or their roles in saving/destroying the world. But godzilla and mothra lemon fanfiction often delves into their relationship in a more personal and sometimes romantic way.
A Mechagodzilla x Mothra fanfic might explore their different natures. Mechagodzilla, being a man - made weapon of destruction, and Mothra, a symbol of nature and rebirth. The story could be set in a post - apocalyptic world where they have to work together to restore balance. Or perhaps it's a story of how their conflict shakes the very foundation of their world. There could be elements of human interference, like scientists trying to control Mechagodzilla while Mothra tries to protect the natural order.
In a Mothra x Destoroyah fanfic, the story could start with Destoroyah causing chaos in a major city. Mothra senses the danger and comes to the rescue. Their first encounter could be a brief skirmish where they test each other's strength. As the story progresses, the author might delve into the mythology behind both kaiju. For example, Mothra's role as a protector of the Earth and Destoroyah's origin as a more destructive force. This could lead to a complex plot where Mothra tries to find a way to either defeat Destoroyah or find a way for them to coexist.
The theme of protecting the earth also comes up a lot. Since they are both guardians of the earth in a way, fanfics may show them uniting against a common foe that is threatening the planet. This can range from alien invaders to man - made disasters. They are often portrayed as the last line of defense for the earth, and their actions can have a huge impact on the future of the planet.
Naruto might also have some cultural misunderstandings at first. For instance, he might not understand the concept of queuing and accidentally cut in line, causing some confusion. But as he spends more time in England, he would learn the local customs and adapt, making friends along the way.