Assit Trophy: Princess Rosalina

Another Mario character far from becoming a character. She'd be be another great option for an assist trophy. She could use a magic spell or something of that sort.

Zelda

Zelda, the far more useful of the two princesses, is another obvious return. She actually is highly useful for several games; including the Ocarina of Time, Twilight Princess, and Wind Waker. In fact, the only game she was useless in was The Legend of Zelda II: Link's Quest, where she was asleep under a spell.