Guarding the Forbidden Grounds for Five Hundred Years, I Betrayed My Sect and Became a Demonic Cultivator

【Fantasy + invincible + no System + ruthless + unaffiliated cultivator + guaranteed thrills】 You say he's your junior disciple, so I can't kill him? Sorry, if I don't kill him, I won't be able to sleep at night! You say he's my junior disciple too? Sorry, I've already left the sect. How could I have a junior disciple? You say you regret it? Sorry, what does your regret have to do with me? A hundred years of struggle, all ending in a fleeting dream. Reborn after ten thousand years, in this life, I will reclaim everything that was taken from me. In this life, I cultivate the Dao for myself alone! Anyone who stands in my way will be killed without mercy!