Very broad strokes, its like a Van Gohh (sp) painting. I see cat and human and little else. Its a comic cover's job to tell us what the story is going to be about, I really can't draw anything at all from this other than eye colors and half a face. I'm also having trouble with your title. Derideal? Deri Ideal? Der Ideal?

Deri -- ???

Ideal -- Concieved or constituting the standard or perfection or excellence. Or, for something to be referred to as the perfection of its kind.

Also the prologue is called "The Dream", and tells me this will either begin with a flashback or of a telling of future plans. Sounds interesting. I really like the detail on the glasses on the man in the middle-ground. The REALLY pointy chin combined with the huge nose leaves me to think "fisheye camera" or "disproportionate and nightmare-like." Both are very strong warping styles for a cover like this, and draws the eye right to the guy in question.

I can't tell what sort of medium this is, but its probably digitally recreated water-colors. It gives it all a very dreamy and not-quite-in-focus feel, which I suppose is the point of it all.