If you thought Superheroes are amazing and doing a wonderful job saving the world. Think about it once more after you view these images. All of them are truly special and have something that no one else in the world has. In a way, they are alone in the world as they cannot share their vision, powers, and past with anyone else but themselves.
Belhoula Amir does a great job at portraying the loneliness of these heroes. He also portrays normal people as being alone in different spaces of the world, where you would expect someone to be isolated from social contact. See more of his work:

A lonely bat
A lonely beast
A lonely genius
A lonely god
A lonely spider
Alone (Field)
Alone (Ice)
Alone (Snow)
Alone (Space)
Alone (Swimming Pool)