How can the new Return To Ravnica mechanic be abused if you are in a Modern format, I would imagine there are a wide array of cards that could make some of these new cards like Growing Ranks, Rootborn Defenses, etc.
I don't bite, don't hesitate to message me if you have any questions or thoughts about deck ideas I post or anything Magic the Gathering related.
My Causal Modern Decks
Swag Flu (Mono Black Infect) http://community.wizards.com/go/thread/view/75842/29788619/Swag_Flu_(Mono_Black_Infect)
American Super Friends (White/Blue/Red Planeswalker Control) http://community.wizards.com/go/thread/view/75842/29772319/American_Super_Friends_(Budget_WhiteBlueRed_Planeswalker_Control)
Hong Kong (White/Red Norin Tokens)http://community.wizards.com/go/thread/view/75842/29636557/Hong_Kong_(WhiteRed_Norin_Tokens)