Time travel in these fanfics can completely reshape the Avatar world as we know it from the original series. If Katara travels back in time and alters the waterbending traditions, it could affect how waterbending is perceived and practiced in her own time. Moreover, the overarching theme of the Avatar bringing balance to the world might take on a different meaning. For instance, if a character goes back and changes a key event related to the Avatar cycle, the very concept of the Avatar's role in the world could be redefined.
The 'agni pravesam short story' might be related to the concept of 'agni' which often represents fire in Hinduism. It could be a story that uses the idea of entering the realm of fire (metaphorically) perhaps for purification or transformation. For example, it could be about a person who has to face a difficult trial (symbolized by the fire) and through that experience, they gain wisdom or a new identity. Without more context, it's hard to say exactly what it's about.
I'm sorry, I'm not familiar with the specific 'agni children story'. It could be a story from a particular culture or region that I haven't come across yet.
Well, in the best ATLA fanfic, the characters are often well - developed. They stay true to their original personalities from the show. For example, Aang's fun - loving and kind - hearted nature is enhanced, not changed. Also, a great fanfic usually has an engaging plot. It could be a new adventure for the Gaang, like exploring a hidden part of the Spirit World that was never shown in the series. And the writing style is important too. It should be easy to read and flow smoothly, making you feel like you're right there with the characters in the Avatar world.