High Martial: Immortal from the Start, I Cultivate by Spending My Lifespan Without Limit

【High Martial + cultivation and leveling up + immortality + burning lifespan + the true myriad races of the heavens + passionate action + later-blooming + slow build】 After transmigrating, Lin Xuan discovers that he has arrived in a High Martial era of spiritual qi revival. Here, demon beasts, Abyssal monsters, and the eerie sweep across the mortal world. Otherworlds, the Abyss, forbidden life zones, the Great Wilderness, and ancient ruins descend upon the world. Humanity is the most insignificant species in this world. It isn't until he turns eighteen that Lin Xuan finally awakens his very own System! Unfortunately, this System is a bit underwhelming: all it does is make him immortal. But... 【Acquired the Heaven-Devouring Art. Spend lifespan to activate it and devour all things in the heavens!】 Oh, then that's fine... Lin Xuan: “System, can I devour that ancient life planet ahead?” System: “6” This book is also known as Burn Your Lifespan to Ascend, I'm an Immortal, and I'll Scatter Your Ashes Thirty Thousand Years from Now!, and Are You Sure You Want to Drag This Out with Me?