User blog comment:Mckrongs/Monster Hunter 4 for the Nintendo 3DS/@comment-3277384-20130918161021/@comment-6050823-20130918203923

Actually, the main reason why Shagaru Magara needs to be killed is because, it's virus will cause everything in the mountains, including villagers, to go extinct while also killing a large number of monsters in surrounding areas(I posted that below).