Paradise Kingdom

After an endless “love affair” with a brave warrior, a legendary weapon, and the demon lord, Seijo, is given a new life as "Kamishiro Hybrid." He becomes a father and feels at peace, but there is his other son, Ushiwakamaru, who is tormented by loneliness. Now that Ushiwakamaru's half-brother has suddenly arrived to take away his place in the world, a “jet-black emotion” starts swirling in his heart, an emotion that no one else can understand. Ushiwakamaru, consumed by the darkness, renounces his morals and declares, "I will create my own kingdom, a Paradise Kingdom..."

(Source: Futabasha, translated)