Well those people were not good people either. None of themwere inocent.
Yes, but they wouldn't have gone psycho had he not hypnotized them. What did the wedding lady really do to deserve to have her mind messed with that much? She likely wouldn't have killed her husband to be if she wasn't having a complete mental breakdown. Also the executive guy likely wouldn't have killed anyone had he not gotten sick or if he lost the job it wouldn't have turned to murder. The main guy put it into his head that the chair was the most important thing no matter what driving him to murder. In a way this series is like code geass with very few able to resist. No human is without sin and it's not like all of them were evil or couldn't have moved on to be better people. It doesn't matter how good the person is with his power he could make the nicest person do horrible things by suggesting it to them.
I think that´s his point tho. That we are all hypocrites and we do anything if it benefit us. I´m not sure what chapter it was but he was explaning this, his real reasoning for killking, to someone.
This manga is interesting, but the main guy is such an asshole. He kills both troubled people that aren't unredeemable and really awful people. I'm glad when he kills the really bad people like the one mother, but I feel horrible for the people like the kidnapped girl, the wedding lady, and the non chairman guy who got hypnotized that he needed that position no matter what. I keep reading because of my morbid curiosity, but I don't like the main guy so mixed feelings on this series.