Cultivation: Fish in Seclusion and Become Invincible

(No female lead, focused on fishing, immortal cultivation, and farming, with a lighthearted path to longevity) After transmigrating to the cultivation world, Lu Shui awakened the [Fishing-to-Immortality System]. While others cultivated bitterly for a hundred years, he cast his line and won rewards. While others risked their lives to seize treasures, he could raise his cultivation just by catching a fish. At first, all he wanted was to live long enough to become an immortal. That was until his hook dragged up ancient spirit beasts, forbidden remnants of souls, and even... Some indescribable being. “System, you call that a fish?!”