Well, in some fanfictions of this kind, Harry might be in a state between life and death. He could be communicating with certain spirits or magical entities that others can't see. His friends, through their strong bond with him, start to sense his presence and then begin a quest to fully bring him back to life. They might have to solve complex magical riddles and face their own inner demons during this process.
Obviously, Harry Potter himself is a central character even though he's thought to be dead. His best friends like Hermione and Ron are usually major characters as they would be the ones most likely to try and find out what really happened or bring him back.
His friends would likely be devastated at first. Hermione, for instance, might throw herself into research to find out what really happened, believing there has to be a way to bring him back. Ron would be in a state of shock and anger, feeling like he failed to protect Harry. They would probably also start to question their own actions and whether they could have done something differently to prevent Harry's 'death'.
One interesting plot twist could be that Harry Potter was actually in a magically induced coma rather than dead. He wakes up with new powers and a deeper understanding of magic. This could lead to him having to relearn how to interact with the wizarding world he thought he left behind.
Well, in fanfiction, 'Merlin Revealed Thought Dead' often creates a lot of drama. It's like a big plot twist. The story could start with everyone mourning Merlin, and then suddenly he shows up. It's a great way to add tension and excitement.
One possible aspect of 'Merlin Revealed Thought Dead' fanfiction could be the shock and awe of the characters upon Merlin's return. If in the original story Merlin was presumed dead, his reappearance would likely stir up a lot of emotions. For example, Arthur might feel a mix of joy, anger for being deceived (if Merlin faked his death), and relief all at once.
In fanfiction, Harry could be believed to be dead for various reasons. It might be due to a powerful dark magic attack that seemed to extinguish his life force. Maybe he sacrificed himself to save others, like in many heroic tales. Or it could be a ruse created by him to deceive his enemies.
Hermione would probably be devastated at first. She might throw herself into researching ways to bring Harry back or to find out if he's truly dead. Ron would be angry and feel guilty, thinking they should have protected Harry better. Ginny, on the other hand, would be heartbroken but also determined to carry on Harry's legacy.
In some fanfics, the plot twist could involve Harry's so - called death being a misinterpretation. He might have been using a very advanced form of magic that made his life - force seem extinguished. He then uses this false perception to his advantage. He might be able to spy on the Death Eaters or other dark forces without them suspecting. He could also be training in secret during this time to become even more powerful and finally emerge to defeat the real threats to the wizarding world.
Neville Longbottom could be a main character. He has always had the potential for great things and in a world without Harry, he would be likely to step into the spotlight. He has the courage and the connection to Hogwarts that could make him a central figure in the fight against evil.