Author's Destiny in The Novel

What if one day you woke up, not as yourself but as an entity entirely different?What if you find out that the World you're now in consists of all the stuff you've ever dreamed about?What if you find out that you're simply an extra, meant to do nothing worthwhile in your whole life? That you're just an insignificant being who'll never make carve your own mark in the Annals of Time.Just what will you do? Will you rise up to fight against your own destiny? To prove your worth to the whole world? Or will you simply accept your fate and lie down for the rest of your life in despair?-------------------------------------------------------------------------------------------------Our protagonist was a successful Novel author, with his novel 'The Path to Transcending Mortality' selling millions of copies. One day on the way back to his home, he died in an inexplicable way, only to wake up in the body of a 16-year-old - Asher Gradivus, an extra who was never mentioned in the novel. Asher soon found out that he seemed to have been transmigrated into his own novel, a year before the main plot begins.70 years ago, The Mythological [Mana] was unsealed and released into the world thus bringing into existence the [System] which would change everybody's life. Dungeons broke out, and new races migrated onto Earth from different worlds. Several higher beings such as the [Gods] themselves started to pay attention to the world. Now, armed with the knowledge of the future, Asher must begin his journey in order to break away from the fate of an Extra he was meant to be, in order to find the meaning to his existence.