Does anyone know a case that would fit an avenger body shape guitar besides the custom fitted one by schecter? I'm thinking a bass case might work but I'm not too sure.
Why not just get the custom Schecter case? Custom fit cases (if available) IMO are the best way to go unless you need some TSA case that will be heavily/extremely abused. The custom fit Shecter cases are well made, tough and inexpensive. They also cradle the entire guitar not putting a lot of stress on any one point of the guitar in case of an accident.
If for some reason the Schecter Custom case is not an option, the next best thing would be the Gator GW Extreme case. It's one of those 'one size fits' all cases which come with shaped foam pieces to fit many different esoteric shapes of guitar.