It could be for revenge, thinking that the humans he's targeting have wronged him in some extreme way. Or maybe he's been brainwashed into believing that it's necessary for some twisted cause.
It might be a psychological thriller. Perhaps the rich man has a deep-rooted trauma or mental illness that drives him to this extreme behavior. Or maybe it's a commentary on wealth and morality, showing how money can corrupt a person's sense of right and wrong.
It's a dark and disturbing story. Such a hunter is likely driven by some twisted motives and poses a great threat to humanity.
It could be a survival situation in a post-apocalyptic world. Maybe resources are scarce and people are forced to fight for them.
Well, it could be that the murderer was after something specific that the old man had, like a valuable heirloom. Also, if the old man had some information that could incriminate the murderer or someone else, that would be a strong motive for killing him. His cataracts might have made the murderer think he was an easy target as well, someone who couldn't identify them clearly.
It could be due to severe mental illness or untreated psychological disorders that led him to commit such a horrifying act.
The story could be one of justice and revenge. Maybe the black man has had personal experiences with the KKK's violence and decides to take matters into his own hands.
Another motive might be related to some sort of dark influence. Suppose Naruto is exposed to an ancient and evil power that corrupts his mind. This power could fill him with hatred towards humanity, making him believe that destroying all humans is the only way to cleanse the world. Like in some stories where dark magic can twist a hero's good intentions.
Perhaps the old man in the painting was once wronged in life and his spirit is full of vengeance. When the person who gets killed comes into contact with the painting, the old man's spirit senses an opportunity for revenge, thinking the person might be related to those who wronged him in the past.
Well, in a fictional and very dark context, it could potentially be about revenge. If a woman has been severely wronged by a man in the story, perhaps in an extreme and misogynistic way, she might be depicted as taking this drastic measure out of extreme anger and a desire to cause the ultimate harm. But this is a very disturbing and unethical concept.
Perhaps they are lonely and seeking new companionship. They might see the man as a fresh addition to their social circle or someone who can bring new energy into their lives.