After playing my badass revolutionary Martin Hawke (love him) and pain-in-the-neck renegade Garrett Shepard (sort of like him) I decided that I'm ready for an evil male Warden. At first I wanted him to be a selfish bastard who makes the worst choices willingly. But then I realised that I would not be able to play with such a character because I need all the actions to be justified at least to some extent. Both Martin and Garrett were aggressive and sometimes cruel, but they were not absolutely evil. I specifically name these two since they are the only male characters I ever played in video games where you can choose the protagonist's gender (alright, I have two more male Hawkes, but they were unremarkable), and my normal type of a game character is a spicy, but generally good female.
So, Isambard Cousland ended up being royally unlucky, somehow aggressive and shamelessly omni-sexual. He still made the worst decisions possible (aside from killing the werwolves instead of killing the Dalish), but he did it either because he had no choice or because he thought it was for the better. Being a Grey Warden he still saw things mostly in black and white and never sided with monsters. By the end of the game I even learned to tolerate him. And I like to think that killing Wynne is the only thing he truly regrets.