You don’t translate the game, you translate the backstory used to flesh out the game. For example, take Niv-Mizzet. In the game, he’s pretty simple: a dragon that lets you draw more cards and do more damage. In the books and flavour text, he’s an incredibly vain, ten thousand year old mad scientist who is one of the effective founders of the city of Ravnica, leads a guild of mad scientist wizards and is also in charge of the utilities.
This could be really, really cool. A movie could be limited in scope to the conflicts of a particular plane (like the technoorganic world of Mirrodin or the gothic world of Innistrad) or it could follow a group of Planeswalkers - the individuals who can safely travel between planes.