Ninja Slayer

Ninja Slayer, aka Fujikido Kenji (フジキド・ケンジ) is the main character of Ninja Slayer. He is a salaryman whose wife and child gets killed in a ninja turfwar. He gets possessed by a mysterious ninja soul known as Naraku Ninja (ナラク・ニンジャ). As Naraku's craving for massacring ninja overlaps with Fujikido's lust for revenge, together they bring Ninja Slayer ( ニンジャスレイヤー, Ninja Sureiyā)– a terrifying ninja killing Grim Reaper - into existence. The more their mental resonance and physical symbiosis deepens, the more powerful Ninja Slayer's karate becomes. If Fujikido completely surrenders himself to Naraku, the strength of his karate will become nearly invincible. He also goes my the name Ichiro Morita (イチロー・モリタ, Ichirō Morita) while unmasked after becoming Ninja Slayer.