Up to this point, and having read several previous reincarnation manga, I can't help but believe that he probably got killed by a "friendly" and not by demons, because he had outlasted his usefulness.
"The demons wanted them to despair". I think the heroes were the demons in disguise to give them false hope. Only to crush that very hope at the last second. Making the fact that John was backstabbed as the heroes killed(?) the maou.
This
... I give this the title of my number one favorite manga. The character development is SUPERB and the MC isn't overpowered. His parents are so loving and caring and aren't little shits like in other manga.
Onion cutters - f*ck you...
Reborn to the past and the mc actually tells people that... this is abnormal sh*t wow. Authors normally be like 'noooo we can't let them know mc from the future/past!!!!!!!'