Originally Posted by Benedict 
Sebastien was a massive letdown after the golem from DAO. Him and Aveline are really dull characters.
I haven't pick Aveline apart during first parts and during some events or personal quests but you interact a lot with her and myself I liked the picture, interesting and not at all dull.
EDIT: From my first play and without to have try Sebastian, in a rough order the most interesting characters was Merrill, Aveline, Varric, and Fenris, Isabella and Anders in the closing pack. Lol forgot Carver, but he is ok and fit the closing pack.