Eric Porthe is a Basic Dispelling Trainer and can teach Dispel levels from 0-3.
Eric can be found Adessa - The Walls usually walking around infront of Adessa Prison, not far from the player's home Sandstone Villa, or in the Arcadium building. Eric can also be found in Adessa - The Isles in the Forum.
More than user reported that, In their game, Eric Porthe was labeled as a persuasion trainer on the map even though he still acted as a dispelling trainer. This glitch can be seen on the Xbox 360.