As of the current manga chapters, Sanemi is still alive. His character has gone through many challenges but has managed to survive. The plot continues to unfold with him as an important part.
Since I don't have specific details about this 'sanemi light novel', it's hard to say precisely. However, in many light novels, the plot often includes elements such as a unique setting, be it a fantasy world or a post - apocalyptic one. Sanemi might be at the center of a mystery or a power struggle. There could be a love interest involved too, which could add an extra layer of complexity to the story.
You can find sanemi fanfic on some well - known fanfic platforms like Archive of Our Own (AO3). There are tons of fan - created stories about Sanemi there. Another place could be FanFiction.net, though the selection might be a bit different. Some fandom - specific forums may also have links to or host sanemi fanfic.
The main character is Sanemi. Depending on the type of light novel, there could be a group of characters around him. For instance, if it's an adventure - themed one, there might be fellow adventurers who each have their own skills and personalities. There could be a healer in the group who takes care of Sanemi when he gets injured, or a strategist who helps plan their next moves. And then there might be a mysterious character whose true intentions are not clear at first, but as the story unfolds, they turn out to be either a great ally or a formidable foe.
In a 'kokushibo meets tanjiro fanfiction', one possibility is that Kokushibo senses something different about Tanjiro right away. Maybe it's the fact that Tanjiro has a unique scent or an energy that Kokushibo has never encountered before. Tanjiro, being Tanjiro, would be ready to face Kokushibo head - on, but also be open to communication if there's a chance. The story could explore their different views on the world of demons and slayers, and how they might come to understand each other better through their encounter.
One great sanemi fanfic is 'Sanemi's Redemption'. It beautifully explores his character development. Another is 'Sanemi's Hidden Heart' which delves into his relationships in a very interesting way. And 'Sanemi: The Unseen Side' is also worth reading as it shows a different aspect of his personality.
For Tanjiro, he could become more understanding of the complex nature of demons. Meeting Kokushibo, a powerful and complex demon, might make him realize that not all demons are simply evil. Kokushibo, on the other hand, could start to have some doubts about his loyalty to Muzan. Tanjiro's tenacity and belief in the good of all might start to chip away at Kokushibo's cold - hearted exterior.
The battle of Yoriichi vs Kokushibo can be found in the advanced stages of the Demon Slayer manga. It's an intense and highly anticipated confrontation. The build-up and action are both masterfully depicted.