It depends on the specific fanfic. Some authors might come up with this plot twist to explore different character motivations and conflicts. In others, it might not be the case at all.
It could also be a completely new character introduced into the fanfiction. A foreign ninja who was inspired by some of Danzo's ideas (not the bad ones) and comes to Konoha to take on the role of successor, bringing in new perspectives and ways of doing things.
Superman's death in comics is often a result of epic battles or selfless acts. For instance, he might face an opponent whose power is just too overwhelming, or he might give his life to prevent a major catastrophe.
Gwen's death in the comics is often a result of a tragic and complex event. Usually, it involves a confrontation with a powerful villain or a series of unfortunate circumstances.
Well, Loki's comic deaths aren't straightforward. It could be as a result of clashes with other superheroes or from cosmic events that he gets caught up in. The circumstances change from one comic series to another.
The circumstances of Gambit's death in comics are diverse. It could be as a result of a betrayal by a fellow hero, or a self-sacrifice to save others. Different comic series present different scenarios.
Daryl's death in the comics was quite tragic. It was the result of a series of events that unfolded, and unfortunately, he couldn't escape it. It was a turning point in the story.