Sanemi’s human blood differs from Kokushibo’s demon blood.
Kokushibo possesses demon blood, which gives him immense power and longevity but destroys his humanity.
Sanemi is a distant relative of Yoriichi, and he inherited his demon slayer mark, which enhances his physical and mental capabilities.
Sanemi is passionate, valuing his sword and comrades as family.
Kokushibo is a cold and ruthless swordsman.
Sanemi faced many demons and near-death situations, leaving him wounded.
Kokushibo can predict and counter opponent movements flawlessly.
Sanemi is more powerful and would win the battle against Kokushibo, as he has more advantages and qualities that make him a better swordsman, a better demon slayer, and a better human.