These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Tiberius is a sickening Serial Killer and Necromancer that even many of his comrades loathe. Tiberius is introduced as an undead Monster Clown who wants 'alone' time with the young heir of the heroic Hadou family Ruri. Once he catches her, Tiberius wastes no time molesting and trying to rape her. When his organization Anticross makes its move, the people of the city are placed in refugee shelters. Tiberius attacks one shelter and take his time slaughtering or violating every living thing, regardless of age, before he moves on to another shelter to attempt the same. when he catches Ruri, he uses her as a Human Shield in his fight with The Hero Kuro Daijuji and wastes no time in trying to rape her and other youthful females he finds during the fighting.
Vespasianus is the Mad Scientist of Anticross who masterminded the C Project, where orphans were taken and raised for his experiments, so he could transform them into superpowered servants for the Black Lodge. One of them tried to escape, which resulted in Vespasianus subduing him and turning him forcibly into the Black Angel Sandalphon. In present, Vespasianus presides over experiments with the Deep Ones where he has them 'breed' with human women and later sacrifices the lot of them before achieving the summoning of the God Dagon, which he knows will wreak havoc. Vespasianius later helps fellow Anticross member Augustus participate in the overthrow of their master Therion with the other 4 so he and Augustus can bind Cthulhu itself to their will. He has Cthulhu violate their captive Nero and later tries to usurp Augustus as well, driven by nothing but a drive to satisfy his intellectual curiosity.
Nya, AKA Nyarlathotep is the true Big Bad of the whole setting, having setup all the events, allowing Anticross to cause so much pain and suffering, as well as their experiments and the bloodshed that resulted. Her cruelty is such that she attempts to create an Eldritch Location where a hero who opposed her is forced to relive his life over and over, coming close to seeing his true love again, but resetting before he could get to her. In the sequel, furious at her defeat, Nya pulls out all the stops to make Kurou and Al suffer, manipulating their future children and using Another Blood's grudge against her mother to convince her to try and kill Al, all the while having full intention of abandoning the children to oblivion as soon as she got what she wanted. Nya's ultimate goal is to release Azathoth and the other outer gods to consume everything, relishing in nothing more than humanity's suffering.