I need help with Pokemon Diamond. Rate my all star team and give advice for the final gym battle?

Hi all Pokemon Diamond players!!! Can you rate my team? I have Piplup, Dialaga, Torterra, Pikachu, Staravia, and Bidoof. Torterra is on level 61 and Dialaga is on level 47. I need advice for the final gym battle. How do I beat Volknor? Should I use my Torterra? It knows earthquake. Also can you give [...] http://bit.ly/dezhjk