Just curious but where exactly do you get a 'seen' entry for Reshiram in Black 2/Zekrom in White 2?
Stumbled across this one during the storyline. Plasma Frigate, in one of the bedbunk rooms (I think one of the left doors?). A Team Plasma guy gives you the entries for both Reshiram and Zekrom. I don't know if he's available postgame, though.