Review Detail of BookDragonling in Rise of the Common Devil [DXD FanFic]

Starts out pretty good but by chapter 12 some inconsistencies begin. Devils vomiting at violence? (these devils were willingly watching potential death matches) Thinking "thank god" instead of lucifer or some other devily alternative? Luckily there has only been one chapter of 'face-slapping' and then none after that. There's also a weird focus on the MC randomly singing songs from the future for some reason. Despite all this, I'm still reading and I know others aren't as particular as I am so give this a try.