There might be a character like Captain Henry, a grizzled veteran of many battles in the 'War of Discoveries'. He has a lot of experience and is respected by his comrades, and he often provides guidance to the younger explorers.
Harry Potter himself is often a main character. Since he has a connection to Voldemort, he's likely to be involved in any dark discoveries related to the Dark Lord.
One interesting storyline could be about a hidden civilization discovered during the war of discoveries. This civilization has unique technologies that could change the course of the war.
However, there could also be new characters introduced. Maybe a mysterious new student who has a connection to the dark side of magic. This character could be a catalyst for the 'dark discoveries' that the story is centered around. They could bring new knowledge or powers that the other characters have never seen before.
Well, the main characters are usually Natsu and Lucy. Natsu, with his dragon - slayer magic, is a powerful fighter. Lucy, on the other hand, has her celestial spirits to aid her in battles during the war scenarios in these fanfictions.
I'm not sure specifically as it depends on the particular fanfiction. It could be original characters created by the author, or it might reimagine existing characters in a new 'salvation war' context.
Perhaps there are original characters created by the fanfiction writer. They could be individuals who have unique powers or knowledge about the multiverse and play a crucial role in the war. For example, a character who can sense the weak points in the fabric of different universes and uses that to plan attacks or defenses. There might also be characters who are versions of existing characters but with different personalities or abilities due to the differences in their respective universes.
In fanfiction, the main characters could be anyone. They might be the leaders of the opposing sides in the war, trying to outwit each other. Or it could be ordinary people caught up in the chaos of the ongoing war, like a young medic trying to save lives on the battlefield, or a refugee family trying to survive the horrors of the continued conflict.
It's hard to say for sure without reading the specific fanfiction, but typically there would be characters who are soldiers. They could be the brave leaders, like a captain who has to make tough decisions on the battlefield.
In this fanfiction, the main characters might include a young and inexperienced ment called Leo. He's eager to prove himself in the war. Then there's the mysterious Sage, an old ment who seems to know a lot more about the war and the ments' history than he lets on. There's also a female ment named Nia, who is a skilled fighter and is constantly challenging the traditional roles of ments in the war.
Sora could be a main character as he is often central in the Keyblade universe. His determination and pure heart would make him a key figure in the war. Another could be Riku, with his complex character and his own journey of growth and redemption.