@Eonlars
Oh boy where do I start? First this
muh special trait removes guilt
Yes "merciless" has something to do by removing her sense of guilt but in case you don't know "All that world is contructed on the idea of killing", all skills are battle oriented (skills like smithing or mining don't exist) and what's the direct poison to the whole idea behind that world? "Mercy". That Title was created to help the system to work as it was in designed.
Seven Deadly Sins and Seven Holy Virtues skill sets
Both skill sets are forbidden by the church on the human world, can you guess why?
Those are powerful (cheat) skills that
than MP as source of energy, but even worse those skills transform the mind of the user to be extremist with that character trait. Let's see what is the worst sin?
Pride.
Anger and Rage are permited because the user can turn off the skill to stop the effect but if your turn off the Sins and Virtues skills it don't stop them to erode your mind.
Even the Demon Lord of Kumo's time didn't dare to take Pride knowing it's dangerous effects, one of them being that the user start to see monster and people as nothing more than
EXP sack (wait that happened on this chapter ?).
Kumo already have Heresy immunity to prevent further damage to her mind but it doesn't repair what is already done.
Kumo was bad (inmoral person) even before the reincarnation
Before the reincarnation Kumo was an antisocial girl with little to no empathy for anyone even her parent. And after the reincarnation she was more worried about her video game character than her parent. Even if she didn't killed anyone Kumo clearly showed the traits of a sociopath.
Let's see the symptom:
- Lack of empathy ✔ (No need to explain)
- Vision of distorted self-esteem
✔ (She's a hikkikomori with low self-esteem)
- Constant search for new sensations
✔ (She really wanted to be hit by those magics and the self-harm with her magic and thread)
- Dehumanization of the victims
✔ (The last scene with the monkeys, the execution of the seahorses and now this with the exp sacks)
- Lack of concern to the consequences
✔ (Taboo)
- Egocentrism
✔ (Not yet on the manga)
- Grandiose delusions
✔ (she's a hikkikomori but in her own words also a beautiful girl)
- High levels of impulsivity
✔ (the new idea of body-in charge that ended with the web on the lava and Kumo's butt on fire)
- Motivation for experiencing feelings of control and power
✔ (Not yet in the manga)
- Panic attacks
✔ (not yet in the manga)
- Schizophrenia
✖
Oh boy what do we have here, Kumo shows almost all symptoms.
With all I have write is pretty obvious that the skills helped her to become what is know but also her moral compass was already broken since the start. Being a sociopath doesn't mean that she was marked to be a killer since the begining she was clearly inclined to commit immoral (or crimes) acts.