Tsugikuni brothers

--- Yoriichi Tsugikuni (継国 縁壱) Basic Information: Affiliation: Demon Slayer Corps (formerly) Era: Sengoku period (over 400 years before the main story) Breathing Style: Sun Breathing (original) Family: Twin brother of Michikatsu (Kokushibo) Status: Deceased Personality: Yoriichi is humble, soft-spoken, and incredibly kind. Despite his unmatched strength, he never boasted about his power and treated others with warmth and respect. He lived a life of sorrow due to the many tragedies he endured—his mother’s death, the loss of his wife and unborn child, and the eventual betrayal by his brother. Abilities: Godlike Swordsmanship: Yoriichi is considered the strongest Demon Slayer in history. He defeated demons effortlessly, including Muzan Kibutsuji, whom he nearly killed singlehandedly. Sun Breathing: The original breathing technique, from which all other styles are derived. Transparent World: He could see the inner workings of his opponents (muscles, blood flow) allowing precise strikes. Demon Slayer Mark: Enhanced his abilities tremendously. Extraordinary Talent: As a child, he defeated an adult swordsman using perfect technique on his first try. Michikatsu Tsugikuni / Kokushibo (黒死牟) Basic Information: Former Name: Michikatsu Tsugikuni Current Identity: Kokushibo (Upper Rank One of the Twelve Kizuki) Affiliation: Demons (Twelve Kizuki – Upper Rank One) Breathing Style: Moon Breathing (derived from Sun Breathing) Status: Deceased Personality: Michikatsu, unlike his brother, was deeply insecure and jealous. He desired strength and immortality, fearing death and wanting to surpass Yoriichi. These feelings ultimately led him to become a demon. Even after 400 years, he never overcame his envy or self-loathing. Despite being powerful, he remained tormented by his failure to surpass his brother.