I can remember the characters used dice to fight. Also, one girl had her legs messed up due to her brother forgetting to keep his dice in check so she got hurt. I remember a guy fused with his monster I believe.
Is it Di-Gata Defender? It was launched from 2006 to 2008 in Canada. It features a group a teen fighting with dice, the youngest is a girl who has been hurt by her brother and has to have prosthetic legs.