I don't see Rage as being used as an aspect for any of the other characters besides Gamzee, really. The parallel could potentially be there, but it seems like more of a "joke" title that is specific to him.
I'm thinking Mom will be a hero of Heart. Bro might be Void since there's a slight parallel between him and Equius. It also makes sense that there would be a Space and Void player in the session, for balance.
Time to go out on a limb: Mage of Heart for Mom and Rogue of Void for Bro.
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You have no time to ponder such questions, as Link has just grabbed a Smash Ball.
http://backloggery.com/herodeltiempo/sig.gif