Board Thread:Game Discussion/@comment-10962369-20130814011435/@comment-11285684-20130814075839

they should have a function that allow you to trade between R cards and A cards.

Eg: you have 5 arcee R cards then you can trade(give back) 4 cards to mobage and receive 1 arcee A card back then you can MTM it. And the number of cards depend on level of rare card, super rare card need 4 to trade, ultra rare card need 3 to trade.