Hell of a Hunter Achievement & Trophy Guide
Clear all missions with S rank.
Clear every mission with a S rank. For the most part, this means performing well in fights and collecting as many red orbs as possible, whether by killing enemies or finding them in the environment.
There are a total of different 21 Missions, including the Prologue, that have to be S-rank in order to get this achievement. They can be done in any order, across any difficulty (not just one difficulty alone). So if you get a S rank on Human mode, then another in Devil Hunter, both will count towards your total. For the prologue, you must perform well against Urizen in order to get S Rank. According to some people, it is not necessary to defeat him if your combat rank was good, but you should at least attempt to actually kill him for a chance at a higher score.
Because this applies across any mode, it is easiest to get in Heaven/Hell, as you will take 0 damage when you one-shot enemies.