Pheonix Wright is a good example of a character that made it into Marvel vs Capcom off of fan service alone but ended up sucking horribly. Though true, he was meant to be a joke character from the beginning.
That said, I doubt SuperBot would have any character that "sucks horribly". If the game is balanced, that won't happen. --- Official Rau/Tati of the Playstation All-Stars: Battle Royale board. PSN:ChocoboDreams