Chapter 1 - Old Wounds
The fight was won , Muzan was finally defeated , but at what cost? Most of the members of the Slayer corp were dead , while those who survived were barely clinging onto life. And their light of salvation , Tanjiro , had been turned into a demon that could walk under the light of the Sun. Despite their attempts to kill him , they were unsuccessful. Kanao stepped in with a syringe filled with the same drug that was destroying Muzan's cells in the fight. She stabbed him in the arm with it , injecting the drug , but he was faster , quick enough to sever his limb with one of his tentacles in time. He threw away Nezuko , who was clinging onto him with what little strength she had after all the blood she lost. All the slayers were barely clinging onto life or were too shocked from the horror they witnessed.
Muzan injected Tanjiro with as many of his cells , only feeling hate towards the demon slayers for being able to stop him. But now , that rage was projecting onto Tanjiro , almost giving Muzan full control over everything. He was no longer an uncontrolled beast , he was the vessel for Muzan. "I gambled and won. I have been able to save myself in time. His body truly is extraordinary , adapting to the Sun in this short of a time. Tanjiro , I had high hopes for you , but you sure exceeded my expectations.". He looked at Kanao , on the ground , trying to get away. "I will kill all of you , and once that happens , I will truly be a perfect being , and then not a single soul will be able to stop me , nothing will , nothing..."
A look of horror dreaded Muzan to his core when he saw a silhouette in the distance. It was no resemblance , nor fear induced , there was a man standing there , the only man he ever feared. "Why is he here?". Yoriichi looked at him , the transparent world gave him a comprehensive sight of the man in front of him. He knew Muzan was dead , but the cells inside the body were definitely his. The voice he had heard earlier was his as well , Muzan had taken the body for himself. The cells going through the blood only became faster with each moment that he was there. Muzan became more and more frustrated from seeing Yoriichi. He understood everything. "Lets end this , Muzan." said Yoriichi as he drew the sword out. The sword was purple , but became red almost immediately upon a slight breath.
This was a shock to Muzan. Even more so the words , as this was the same man who sliced apart his cells in a such a way that they could barely hold together , let alone heal after hundreds of years. But he couldn't let himself be outmatched this easily. He had finally overcome his one fatal weakness , and he wasn't gonna let anyone defeat him. He extended the tentacles on his back to attack Yoriichi. Of course , being faster , he dodged the attack , ran on top of the tentacles , slicing them in the process. He came towards him and slashed off his head. "It hurts..." thought Muzan to himself "... but it's manageable. Even his technique won't be enough to stop the regeneration now.".
Muzan flung around the tentacles , knocking Yoriichi back quite a distance. He crashed straight through a wall. No serious injuries , but that was still too close for comfort. He knew he might not be able to defeat Muzan , but he had to try. They both saw what the other was capable of. They weren't gonna let the other survive. Muzan fired an energy ball at Yoriichi , which he detonated when it got close to Yoriichi. Despite exploding , it didn't do much damage to him , only propelled him closer to Muzan. Yoriichi didn't use one simple form of the Sun breathing , but rather chained it into the final form in hopes of ending Muzan right there. But even with that , the blood was resilient , and so was Muzan now. He let out an electrical discharge , zapping the ground. Yoriichi jumped off of Muzan's back just in time to avoid being electrocuted , but was still able to feel some discomfort in his legs from his sandals touching Muzan's back. Muzan was becoming more and more annoyed while Yoriichi could only try and think of a way to kill Muzan.
The fight was not going to be short , and it wasn't going to be won without either of the 2 forces struggling.
Chapter 1 , complete
Ok , I might not be the best when it comes to writing fighting scenes , I have a clear vision of how they'd look , but I have almost no idea how to properly write it down on paper. This chapter was a bit required to have an explanation as to why Tanjiro was now Muzan , so I'm sorry that it took a bit from the chapter. This is the first of 3 chapters. Next chapter will explain how Yoriichi even got here , and will have some combat in it , further delving into Muzan's cells progressing from the influence of Tanjiro's body , so it'll probably be longer then this one. 3rd one however , for the most part , will be combat based , so I hope that in the meantime , I'll get some feedback on how I could improve writing the fight sequences to be better.
Stay safe people.