Once Ren figures out what his power is (shapeshifting into a knight with a vaguely magical sword), he'll probably be using it to try and break into rooms whenever he gets restless - so it'll be a bit of a sporadic thing when he does it, but probably add up to a fairly decent chunk of time over the course of different attempts (due to the nature of his powers, it can't be any more than six hours in a day, I'd say he's probably not focused enough to keep doing this for more than about two or maybe three hours a day anyway). He'll probably mainly start out with doors further away from the rooms that he considers to have a higher chance of being overlooked.