I'm too old to be isekai'd!

Andres, a middle aged father, wakes up in an unfamiliar world.
With an unfamiliar name, donning an unfamiliar face.
A world where mana and technology co-existed.
Where humanity did not solely rule the planet.
Races and creatures thought once as myths now exist as they vie for control on the once conquered world.
Amidst all this confusion, a sense familiarity.
As if he has heard of this place, somewhere, at a different time and place.
"So God has a name? What is it again? Arcus?...."
"I feel like I've heard about you before... Rowan was it?"
As the pieces start falling into place...
"I can't believe I got isekai'd into my son's novel..."
A fate surely worse than death.
'Remember son, it's darkest before dawn.'
A mantra he once used to provide a semblance of control on his life.
Passed down to his progeny, has come back to bite him in an unexpected way.
In order to survive and return home, he will need to prepare himself.
With his knowledge of what is to come he will tip the scales ever so slightly in his favour.
But there's one small problem...
"Which one of my son's book am I in?"