Polen is a grunt in Team Netherworld the criminal orginization. His goal is to stop people from ruining Dakim's plans. He is first battled in Netherworld's Veilstone city hideout. Later he is battled at Mt. Coronet, however, he was defeated by Diamond and Pearl. After that he is never seen again.
Pokemon at Veilstone Hideout Battle
Pokemon At Mt.Coronet Battle