Thunderman is Raoul's net navi, and like his name suggests, his main power is electricity. His power seems to exceed that of Elecman's, in the fact that Rockman finds the Elec-sword is very unaffective against him (which is what he used to once defeat Elecman).
Thunderman continously helps Raoul protect the people who live in the downtown area of Amerope from the evil Mayor. Past this, Thunderman enjoys a good ole sparring match with Rockman from time to time.