First off there is never a bad question.
To answer your question If you played in the ELO mode and finished with a score of over 1050, you can vote to keep or ban a particular character. The higher your ranking was at the end of the previous tournament, the more votes you can cast.
There is a list of cards that can be banned here: http://www.urban-rivals.com/game/elo/vote.php
Hope that helps if you want more info feel free to PM me anytime.