Kenpuu Denki Berserk, Dororo Recommendations
Badass main characters slaying monsters with side characters that keep growing as characters and become stronger.Guts and Hyakkimaru are both indifferent towards people but kind. They are also both inflicted by a curse. If you are a gamer, Dororo anime is basicaly like the Witcher.
Both shows plot revolves around two men chasing demons in a medieval setting, Dororo in a fantastic feudal Japan and Berserk in a fantasy-like Europe. Both shows also deal with the horror of the war and the hopelessness of the ordinary people, filled with heartbreaking subplots that afect the life and world views of the show's main protagonists.
Extremely similar story elements between the two, about a brooding swordsman who lost several physical attributes and hunts and is hunted by the roaming demons of the world, and seeks revenge on the one who did this to him and spawned the demons on the world.