The scariest plot twist could be that the world around him is not what it seems. He finds out that the desolate earth he has been living on is actually an illusion created by an advanced alien race. They have been testing human endurance and when he discovers this, they start to slowly break down the illusion, revealing a grotesque and nightmarish world filled with alien creatures that he can't possibly fight against.
One scariest plot twist could be that the last man discovers he is not actually alone. There are some other entities that have been observing him all along. These entities are not human but something far more sinister, like shadowy figures that can move through walls. He thought he was the last hope for humanity, but now he realizes he is just a part of some sort of experiment by these unknown forces.
Maybe the last man on earth starts to see his own doppelgängers everywhere. At first, he thinks he's just hallucinating due to loneliness. But then these doppelgängers start to interact with the environment, leaving things in disarray. He realizes that they are real and seem to be draining his life force every time they appear. It's a terrifying thought that he has to face not only his solitude but also these strange and menacing duplicates of himself.
It could be an ordinary guy. Just an average person who happened to survive whatever catastrophe wiped out the rest of humanity.
Well, it could be about survival. Maybe he has to find food and water all by himself. He might also face threats from nature like wild animals or natural disasters.
Well, it could be about a man trying to survive in a post - apocalyptic world all alone. Maybe he's searching for other survivors while facing challenges like finding food and shelter.
The last man could cope by documenting his experiences. He could write in a journal or record videos. This would be a way for him to process his emotions. He might also leave a record for any possible future survivors or other intelligent beings that might find his work. Through this, he can externalize his feelings of horror and also have a purpose in his solitary existence. Also, he could try to find some form of spiritual or philosophical meaning in his situation, which might help him better face the horror.
It could involve the last man's struggle to survive in a desolate world while also dealing with his own loneliness. Maybe he discovers a strange lemon - like plant that has some sort of special property that helps him in his survival. For example, it could provide him with a new source of energy or have healing abilities.
Well, the plot could be that Naruto is the sole survivor after some kind of apocalyptic event. Maybe all the other shinobi were wiped out by a powerful enemy or a deadly disease. Naruto then has to find a way to rebuild the world while also dealing with his loneliness and the memories of his lost friends.
One possible ending could be that the last man simply gives up and succumbs to the loneliness and despair. He might just lie down and wait for death to take him.
The isolation. Just the thought of being the only person left on the planet is terrifying. There's no one to talk to, no one to help you if you get into trouble. You are completely on your own in a world that has become a huge, empty and often dangerous place.
It could be extremely terrifying. Just imagining being the last man on earth means no one else for company, no social interactions. There would be a sense of utter loneliness and desolation. Everywhere would be silent and empty, with no signs of human life except your own. It might also imply that there are unknown and perhaps menacing forces that led to this situation, which adds to the horror factor.
The 'the last man on earth shortest horror story' is likely to focus on the psychological horror of the situation. The man is the sole survivor, and he has to deal with not only the physical world around him but also his own mind. He might start to question his own sanity. For example, if he sees something out of the ordinary, he has no one to confirm if it's real or just his imagination. He also has to face the finality of being the last, with no hope of a future for humanity as he knows it.