Lets open up with some character design.
The goal is to design anoriginal character with a specific theme.
The theme is pretty vague, in fact it can almost be anything. Design a character that embodies a non physical idea or concept. Examples are feelings or emotions or more abstract ideas. The more abstract your idea is though the harder it might be to make a good design that embodies it.
Think rage, sadness, love, death, war, famine, etc.
Common characters like this are the four horsemen of the apocalypse, or the seven deadly sins. Generally they need no introduction and their theme is obvious without you having to tell anybody what it is. That quality specifically should be your main goal. Don't tell anybody what your character is supposed to represent though and see if people can guess what it is when you post it. If they can you probably did a good job. If they cant, not so much eh?
Good luck then.