Since I haven't read the 'alone on the water fanfic', I can't say for sure who the main characters are. But it could be a lone sailor, an adventurer, or someone who has been stranded on the water.
There's no way to know exactly who the main characters are without reading the 'alone on the water fanfic'. But it could be someone with a special connection to the water. Maybe it's a mermaid - like being who is alone in the water, away from her kind for some reason. Or perhaps it's a human who has a mission on the water and is left alone to complete it, facing all kinds of challenges along the way.
It could be a mermaid or merman who is alone in the ocean for some reason, maybe banished from their community.
It could be a young trainer who prefers to journey alone. They might be the central character, facing Pokemon battles and exploring the world on their own.
Since we don't have much information about this fanfic, the main characters could be various. It might be a group of adventurers, where one of them is wearing the armor. Maybe there is a female character who is an expert in water - related magic or technology and she teams up with the armored male character. Another possibility is that the main character is a young person who discovers an ancient armor in a watery cave and then has to deal with the consequences of wearing it in the water - filled world around them.
I'm not sure specifically as it's a fanfic. But it could be characters from the original source material that the fanfic is based on, who are now put in situations where they fight alone.
Well, 'alone on the water fanfic' could potentially revolve around a person's journey while being alone on water. Maybe it's a fan - created story based on an existing work where a character finds themselves adrift at sea or on a lake all by themselves. This situation could lead to various plot developments, such as encounters with strange creatures, or simply a deep exploration of the character's thoughts and emotions in such a lonely and exposed situation.
Since I haven't read this specific fanfic, it's hard to say for sure. But it could be Harry Potter, of course. Maybe Hermione and Ron are also involved in helping the 'no longer alone' aspect, like they do in the original books, by being his friends and comrades.
I'm not sure as there isn't much information given. But it could be an ordinary person who has to face challenges alone.
It could be about a character who is lost at sea and has to face various challenges alone, like fighting off sea monsters or surviving a storm.
The main character is usually the water dragon slayer himself or herself. They often have unique powers related to water manipulation, like creating water whips or tidal waves. Another common character is the mentor, who could be an older dragon slayer or a wise mage who teaches the protagonist the ways of slaying water dragons.
I'm not certain. But usually in such novels, there would be a protagonist who is likely to be closely associated with the events related to the water. Maybe a detective or someone with a personal connection to the water - related mystery.