idea's for my book. the book of the damned.

in a world govened by rpg video game rules character's! have to ttravel through the laberinth of sin. facing demon's and overcoming desires on the first floor where lust rules. i've written 4 chapters but i am stuk. Parker and troy: the main character's were from earth and are about the face the prince of the orcs with no way to fight or protect themselves. Any one have any idea's on what could happen. i'd love any idea's or beedback on my story idea. As an rpg adventure story. character's receive class's and abillities. skills and manna. quests and rewards. the money of the realm is mostly credits given by the system though some things require gold: silver and things like that.
brainstorming?
i have been brain storming of the last two weeks and the synopsis of my book is something like. in a world where magic and video games clash a realm on the edge of demonic incurtion and about to be plunged in to darkness: the laberinth of sin has once again risen from the depth's of the abyss. Bringing the 7 deadly sins to the world. 2 humans from anzther world are summoned as outside forces clash with the hero association a long awaitered prophicy begings to unfold.
I researched the 7 deadly sins and the names of the demon's that are post closely linked the each sin: such as: lilith and lust: lucifer and pride.