Responses
I understand your point, and normally would agree 100%, the only thing that makes me a little doubtful is the fact that the grandma would die a little later anyway. Making someone suffer for the rest of their lives to extend another person life for a little while sounds really bad too.
Honestly, I don't know what I would do in MC place. Maybe I would try to communicate with his friend that controls the game to make another option... But it's a really hard decision, and no matter what he chooses it will make him feel a lot of guilt.
I'd choose to save my grandma tbh. Like i feel bad for ml for injuring his legs but even when he did he managed to become successful in the novel. I know he can do that again this time too. On the other hand the grandma will literally die. It's an easy pick tbh