Transmigrated into the Extra Chapter as an Extra

Arzen gets transmigrated into the novel "I Become a Business Tycoon After I Regress," arriving after the main storyline has ended. He ends up as an extra in an extra chapter focused on the adopted child of the protagonist couple. Without any knowledge of what's coming next and no special resources or magical systems to help him, how will he manage and survive in this new world?

Cover Art by pi4nno