These words are used so lightly nowadays, but in terms of literal raw seinen chadness, there's not a single manga/manhwa character alive outside Guts/Kenshiro/Kingdom's Great Generals that can rival Vagabond's best, and among them, Ito Ittosai, my favorite is ranked quite high.
You know that your alphaness can't even be measured by DBZ's scouters when you encourage both the protagonist and the main antagonist to become like you. He was historically responsible for creating the Ittoryu Style which was his own swordsmanship style, which OP Zoro uses.
Musashi ( the man who claims to be invincible under the sun, single handedly steamrolled an entire squad of 70 professional fighting samurai school ) and Kojiro ( the combat prodigy ) couldn't topple him. He literally raised two reapers. and this shit is impressive since Vagabond's top tiers are literally, basic human beings who consider cutting flesh and bones with one arm to be notable, with Ittosai being able to do it with one arm that has lost half of its fingers.
It's definitely not his strength what makes him a candidate for this chadness list, but his own perception of what it means to be "unrivaled under the sun" which Takehiko Inoue delivered tremendously with his Kingdom Tier art and smooth world building. one would definitely not feel the intensity and the meaning behind it unless he reads the first three arcs of Vagabond.