You want Shin to kill a normal important(lol) human of some country and make him into a true maou in the eyes of all stupid common people? Yeah no thank you. That will only make this story 180 into the dark. And a lot of story with 180 change are very much traumatic experience for the weak me.
I can accept all the "X should win", "X best girl", or "harem end ftw" comments. But everyone who says "X should gtfo", "I won't accept it if X win" etc are just being a d*ck.
From what I see, all of this about working is Uzaki's plan. The two only agreeing with her. The thing about 'it's not natural' is if the plan and all comes from Asai or Master or from someone unrelated like the busybody guy.
Be realistic, guys. Put a real modern guy in the MC's shoes and you won't get someone who can overcome his fear with only one year without a mental break even if they're accompanied by a very strong legendary beast. More so if the person himself is actually have a weak status with slow stat up...