Every artist has deep felt emotions toward almost anything they do. It is this way that we find out how great artists are regardless if their works are of one’s preference and not. That strong emotion is often referred to as the soul of an artist on which reflects the artist’s heart and thought. Thus, the origin of Soul.
Being a dark artist doesn’t mean your works are evil. When you classify an artist something as “dark”, it only meant that that certain artist could see though deep in most things. Though interpretations are mostly of the cynical and perssimistic side, the strings attached to reality never leaves.