I Guarded Against Demons for a Hundred Years, and Now I’m Invincible Under Heaven!

After transmigrating to a xianxia world overrun by demons, with poor aptitude, Zhang Zhiwei can only become the guardian of a demon well? Luckily, he awakens a God-Tier Choice System and is bound from the start to the template of the God-Tier Old Celestial Master, with maxed-out comprehension!! Cultivation has never been about fighting and killing... Faced with countless choices, Zhang Zhiwei is ready for anything. Wait, with the Old Celestial Master's talent, why not cultivate into a mortal-world immortal instead of coming down the mountain? Wealth, companions, techniques, and a blessed location? With the Old Celestial Master's talent, do I need any of those external things? Of course, if you insist on giving them to me, the Old Celestial Master will take them too. Through his choices, he receives so many rewards he can hardly keep count: the Golden Light Mantra, the Five Thunder Orthodox Method, the Heaven Communicating Talisman Art, the Six Treasury Immortal Thief... He has all of the Eight Extraordinary Skills, along with the Heaven-Devouring Demonic Art, the Divine Elephant Suppressing Prison Force... His cultivation instantly reaches the god tier!! And so, a thousand years later, the name of the peerless Old Celestial Master of Longhu Mountain is renowned throughout the world! One day, demons and fiends wreak havoc across the Nine Provinces, leaving the land devastated and its people suffering. No one can stop them. A towering golden figure wreathed in thunder descends the mountain to purge evil for sixty years! Everyone worries: The Old Celestial Master has never fought anyone before. After a thousand years of bitter cultivation, could something happen to him? The demons and fiends wail: ??? No wonder he hits so hard! One slap, and every single one of us goes flying! Has he surrounded our whole group all by himself?! The Demon Ancestor and Fiend God were both blown apart with one slap!!! Old Celestial Master: I, Zhang Zhiwei, am the Old Celestial Master of Longhu Mountain! Has anyone never lost before... Everyone: This is the real Old Celestial Master! Obey him, and you're second only to him, like The Outcast! Disobey, and you'll get one hit each!!!