Malal
Followers of malal are kind of like Chaos Atheists. They doubt that anything exists, including the emporer, god, chaos itself, and you. Especially you.
The followers of malal's mortal enemy is the ghost of "[1] René Descartes", a french philosepher who made up the quote, "I think, therefore I am.". Not only do the followers of malal doubt that they exist, even though they still think, but doubt that the stement is true. Also, they doubt that they doubt that the statement is true. They then doubt that they doubt that they doubt that the statement is true. As you can see, this leads up to a lot of rage and frustration (though no where near the anger of theAngreh mahreenz.
Malal himself is the god of doubt, but I doubt that he actually exists.
There are no pictures of Malal. I doubt that a picture exists.