In the fanfic, it could be that Arceus has its own reasons for allowing Ash to catch it. Maybe it sees Ash as the key to restoring balance in a world that is slowly being corrupted by human greed and over - exploitation of Pokemon resources. So, as Ash catches Arceus, he is thrust into a mission to cleanse the world. He might have to travel to different regions and use Arceus's power to heal the damaged environments and reconcile the differences between humans and Pokemon.
In these fanfictions, a common element is the role of Ash's friends. They might either support him directly or be in some sort of trouble that Ash needs to solve with Arceus's power. Additionally, the power of Arceus is often depicted in a very unique way. It could be used to heal the Pokemon world, or to restore balance in some way. And of course, Ash's own growth as a trainer is always a central part, as catching Arceus is like the ultimate achievement in his Pokemon - catching journey.
A possible plot development could be that Gible evolves during their time in Kalos. This would give Ash a more powerful Pokemon to compete in Kalos gym battles. Another development could be that Gible discovers a new type of move or ability while in Kalos, which gives Ash an edge in battles.
One possible plot is that Latias is injured and Ash finds it. He nurses it back to health, and during this process, they form a bond. Latias then decides to join Ash's team. Another plot could be that there is a tournament where the prize is a special item that can attract Latias. Ash enters the tournament, wins, and uses the item to catch Latias.
Well, in many such fanfictions, the story often starts with Ash stumbling upon a very rare or dangerous situation that leads him to encounter Arceus. Maybe he's exploring a mysterious new region and discovers something that Arceus is involved in. Then, through his typical determination and kindness, he manages to form a connection with Arceus. This could involve helping Arceus out of a tough spot, like being trapped by some evil force or being affected by a strange phenomenon. And finally, Arceus, seeing Ash's pure heart, allows Ash to catch it, which then changes the whole dynamic of the Pokemon world in the fanfiction as Ash now has the most powerful Pokemon by his side.
Well, it could be about Ash traveling to a remote area, like a hidden forest or a mysterious island where the rare pokemon is rumored to live. He might face many challenges on his way there, like tough terrains or other aggressive pokemon. Then, when he finally encounters the rare pokemon, it could be a really intense battle where he has to use all his skills and knowledge of pokemon to catch it.
One possible plot twist could be that the legendary Pokémon start to lose their powers once caught by Ash. Another could be that there is a hidden cost or consequence to catching all of them that Ash doesn't initially realize.
One common theme is the power - up of Ash. Once he catches Arceus, he often becomes an even more formidable trainer. Another theme is the exploration of the relationship between Ash and Arceus. It could be a respectful partnership or Arceus could act as a sort of mentor to Ash.
Yes, there are quite a few. You can find some on popular fanfiction websites. Some might focus on Ash's epic journey to catch Arceus, with detailed battles and his growth as a trainer along the way.
Maybe Ash's sickness is caused by a new and mysterious Pokémon. As he's sick, he starts having strange dreams about this Pokémon. His friends then start to investigate based on the details from his dreams. They discover that this Pokémon has some sort of special power that is making Ash ill. In order to cure Ash, they have to find and befriend this Pokémon. They go through a series of adventures, facing other Pokémon and trainers, all while Ash is lying sick in a Pokémon center.
Ash could catch Latias in a place full of ancient ruins. Latias might be guarding some sort of Pokemon relic there. Ash shows respect for the place and Latias' role. This makes Latias interested in him. Eventually, Ash catches Latias and they go on to discover more about the relic's power together.