У вашего броузера проблема в совместимости с HTML5
http://www.gamefaqs.com/boards/684236-dragons-dogma-dark-arisen/66131546 - To make Death appear frequently, I've used this method.
For this fight it seems that the Striders are really good on doing great damage on him with their Brain Splitter attacks and Hailstorm Volley.