As of the latest chapters I've read, Megumi is still alive in the manga. Usually, such major character deaths are significant plot points and would be well-publicized if they occurred.
Typically, megumi fanfic often focuses on his personality traits. His stoicism and determination are often highlighted. For example, in many fanfics, his unwavering resolve in the face of danger is a central theme.
Well, Megumi's story in the manga was full of twists and turns. She had to overcome various obstacles, and there were also some unexpected developments in her relationships with other characters.
Nope, Megumi is alive. The author has chosen to keep Megumi's character alive to continue developing their story and interactions within the manga's world.
One of the main themes might be mortality. Given the title has 'Death' in it, it could explore how characters face death, whether it's their own mortality or that of others. Another theme could be the search for meaning. In the face of death, characters may be on a journey to find what makes their lives meaningful.