His appearance doesn’t fit the Oberyn image I had in mind (I had imagined someone darker and more Middle-Eastern looking), but I don’t want to give a certain opinion without seeing his performance.
I mean, Peter Dinklage is far more handsome than book!Tyrion, Gwendoline Christie is much prettier than book!Brienne, Nikolaj Coster-Waldau doesn’t have the ambiguous facial features the books describes (since it’s said Jaime and Cersei look very alike) and so on… I’m sure I can think of several other examples if I think about it. But they’ve all done a fantastic job. I think Game of Thrones casting is brilliant, the only person I’m not entirely happy about is Joe Dempsie as Gendry.
So I’ll hold judgement about this new casting decision until I’ve seen Pedro Pascal’s acting.