What is the worst type of rarepon on Patapon 2

In terms of usefulness, the "Wanda" rarepon would be considered the worst. It may be cheap and useful to the army in the beginning of the game, but it's weakness towards fire makes it next to useless when you fight Dragon's to get metal or fighting regular enemies because of their fire weapons. You'd be better of using the Chiyobi rarepon of keep trying to get the other rarepons. Hoped this helped.