you know shits bad when even demon slayer can do the same kind of shit (oh woe is me villains) and handle it better.
Demon Slayer never actually has its characters hesitate or show mercy because of their opponents past or pain. Tanjiro still kills every demon he fights, he just somehow manages to retain a functioning sense of empathy towards the nightmare monsters he's killing.
The closest anyone in Demon Slayer comes to "forgiving" a demon is Tanjiro killing the one spider girl painlessly when she was literally begging him for death.