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.
Apos, with his golden hair, crimson eyes, and beautiful features resembles an angel. The truth is markedly different. Apos is an immortal who finds amusement in suffering and agony. Apos hunts down female immortals and rapes and tortures them physically and mentally to consume their 'core' of immortality. The suffering improves the taste. Apos's obsesses over the heroine Rin Asogi and has his female subordinate Laura disguise herself as Rin to ruin Rin's name with a series of murders, and also satisfy his lust by raping her. At one point, he brutally crucifies and rapes Rin's best friend and lover Mimi simply because he was bored waiting for Rin's arrival. Apos is behind nearly every evil plot in the series and engineers a plot to turn the world against immortals and turn on itself by causing a nuclear explosion with an immortal seen as a survivor, before revealing the world tree Yggdrasil to the world to have humanity infected with the time fruits and become immortal so he cna harvest them at leisure. Apos betrays Laura and forces Rin to kill her old lover apos had turned into a carnivorous Angel in self defense, before personally executing her current lover (Apos's own father) and attempting to sacrifice Rin to Yggdrasil. When asked what he wants with the world, Apos's response is simple: I want to taste it!
Sayara Yamanobe, second only to Apos, is a repulsive, callous scientist, who masterminded the cloning program that killed the original Koki Maeno. She keeps the failed test subjects as ravenous, flesh-eating zombies that suffer every moment they're alive. When she has Rin in her care, Sayara proceeds to molest and then torture her to death while it's more than just implied that she molested and raped Koki as well, also being hinted this is routine for her. Sayara later just tries to wipe out all human life and she would be the morally lowest character in any other series, so it says a lot about Apos that he's the lowest, the most depraved and the most disturbing one in Mnemosyne.
Episodes 1 and 2 seem to be made to test just how far you can push the network executives before they bring the censors crashing down on you. And quite frankly, it seems to have succeeded, as the violence and sexuality of Episodes 3 and 4 are practically benign in comparison to their portrayals in Episodes 1 & 2.
Though almost as if flicking a giant middle finger at the networks for suppressing them for 2 Episodes, the Director crosses the line thrice with the nightmarish Episode 5.
Cranked up from subtext to text-text in the second episode. And it goes beyond that later, up to and including a full-blown lesbian orgy, with Mimi at the center.
Ironically, the most that ever happens between Rin and Mimi onscreen is some kissing and groping.
Narm: Apos. Sometimes he gets so...over the top (for lack of a better word) he comes off as less of an Evil Genius and more of just an annoying Bishōnen.
Tear Jerker: Maeno Kouki's Wife's reaction to his death in episode 3, as well as Ihika's death in episode 6.
The Woobie: Yuki who first loses her brother Shogo, then years later loses her husband Kouki, leaving her to raise their son Teruki alone. Add to that she never finds out what happened to them, is basically Locked Out of the Loop and seldom seen smiling.