My friend , in my opinion in order to have a good base for an AVN you have to write the beginning of the story ,create the basics about the characters (name,gender,character,powers ,abillities, race) all these are prep work , without it you will loose the plot on the road ,for example in the beginning of this AVN the MC has locked powers , after an extentive period of imprisoment,torment and injuries he breaks free killed or not the ruler of hell and absorve his fire controling abilities ...But there is no explanation on how the hell did he manage to do all that since he supposedely at the time had no powers....
My point is to write a good story you have to know the answer to Who?When?How ?and Why?