I already detest this mc enough as it is for his adamant refusal to do what he has to do and what any normal person would do in order to end all the chaos. But what's worse is that he has no logic to back up his bullshit. You would rather sit back and watch many innocent people die at the hands of a serial murderer when you could easily use the power you were given to end his rampage. Then you go and cry like a little bitch because people are dying and refuse to acknowledge the fact that you could prevent it from happening.

Villian: "I'm gonna go kill 100 people."
Comrade: "Use the white arrow!"
Fucktard mc: "But no one deserves to die, not even a serial murderer."
*100 innocent people including women and children dies*
Fucktard(+1) mc: "Boohoo, why do people keep dying?"

Then you go spouting some bullshit about not killing because you want to protect the "happiness" of you comrades and the people around you. So then, what about the happiness all those that have died because of your horrible decision making. Apparently ending the life of a single person that greatly deserves it would weigh on the mind more than the lives of all the people who you let die. You just let ugly dude die and put cat girl in danger because you spent 5 fucking minutes thinking about the fact that you won't kill the psycho chemical weapons bitch. And wow, she died anyway, so what was it all for?
I can confidently say that this is the worst mc I have ever come across in all my days reading manga.
At this point I just wish the villain, whatever the asshole's name is, would put a white arrow in the mc's head so we can just be done with it since the mc clearly won't do it.

It's even worse when he doesn't mind if his comrades kill the villain as he approve of it. Honestly he's being very selfish as it is mention it is for his own happiness and no other reason, not even moral related. It shows the main character being cowardly (as he needs others to do the killing) and a hypocrite as he shows indifference when the doctor girl died and him not minding his comrade killing the villain. If you want to see a likable character that hates killing in a more nuanced and a more well written way see rurouni Kenshin instead.