That's what made Dukat a complete character in my opinion. That he did have some redeeming qualities. During seasons 3, 4 and early 5 he was practically one of the good guys or at least on their side half the time. Sure he had his own reasons for working in alignment with them, but it stops and makes you think. Really if he toned down his ego and wasn't always out for himself, he might have been able to experience a turn around like Damar did. But removing Dukat from his ego is like trying to remove an the egg from the omelet.