Demon Slayer: Demon Slayer: Living Blade

As a die-hard Demon Slayer fan, I suddenly traveled into the Demon Slayer world while watching the theatrical version and became a demon holding a Nichirin sword. How should I, who is familiar with the plot of demon slayers, save the pillars who were killed by demons? What is my identity now? Why can I use breathing techniques and blood ghost techniques? How do I turn the Pillar-Destroying Blade into the Pillar-Living Blade? This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.