Traveling Through Troubled Times, I Rely on Kowloon to Become an Immortal All over the World

Lin Chen was brought to Lanjie by the Nine Dragon Jade Pendant. The world here is polluted by aliens, everyone is shackled, and they can no longer reach immortality! However, a very high technological civilization has been developed as a result. As a visitor from another world, Lin Chen has no differences in his body and his path to immortality is unimpeded. Relying on the power of Nine Dragons, various magical powers are awakened. He can fly with a sword in his left hand and shoot with a gun in his right hand. It can be called the first person in ancient and modern times... (This is my first time for a newbie to write. Please take a look and give me your opinions.)