Demon Slayer: My Sword Skills Aren’t Just Special Effects

【Elemental Swordsmanship That Isn't Just Special Effects】 After transmigrating to the Warring States period, his mission is to eliminate the Demon King Muzan? Shangchuan Qingxuan glanced at the young man beside him, dressed in a scarlet haori, and thought that as long as he warned him to watch out for the scumbag boss's “Three Thousand in One Breath,” things should be fine, right? Such a simple mission, surely nothing could go wrong... 【System Notice: Your affinity with this world is too low. Your talent, “Elemental Affinity,” will make the world reject you.】 【System Notice: You have contracted a rare blood disease. Remaining life expectancy: 3 years.】 Shangchuan Qingxuan, who didn't have Muzan's fate but had gotten Muzan's disease, was stunned. “Scumbag boss! Get your attending physician over here. It's urgent!”