15 Sept 2013
An ability that triggers when a creature becomes monstrous won't trigger if that creature isn't on the battlefield when its monstrosity ability resolves.
15 Sept 2013
When the last ability resolves, the active player will choose three lands they control, then each other player in turn order will do the same. Then all of those lands are sacrificed at the same time.
15 Sept 2013
Monstrous isn't an ability that a creature has. It's just something true about that creature. If the creature stops being a creature or loses its abilities, it will continue to be monstrous.
15 Sept 2013
Once a creature becomes monstrous, it can't become monstrous again. If the creature is already monstrous when the monstrosity ability resolves, nothing happens.