Important Question

1. Do you want to this R-18 JJK fic to move at fast pace? Meaning getting straight to the point of each important arc of JJK meaning more time to meet all the characters of JJK. Meaning some time-skips here and there. 

2. Slow pace you will see MC family life and some of his training etc.

For me I would pick number 1. As I want to get straight into the action most JJK fics take forever to get good and all the MC are weak simps on WN, but my MC will become OP and yes a anti-hero but not full on villain. Think of MC like Batman but with killing intent.