Pushing back inevitability (rewrite)

"Clean, well written action-driven adventure, possibly a script for a mass online video game. Our protaganist starts off as a fat IT slob with bad teeth lliving with his dysfunctional parents before he gets picked by a minorr deity as one of 100 million heroes to save the world. He quickly shows himself adept at killing off ratmen and breaking their altars. He trims up, fixes his teeth, cleans his room and moves out, becoming more likeable, and takes the fight to an inter dimensional enemy invading earth through 1,5 trillion portals."