Why is the fourth person from the elite four there in the library (canalave city )

Ummmm first: Elite Four Lucian is guy. And he is in the canalave library exclusively in Pokemon Platinum after you beat the Elite four. Its just the way they desighned the game. (P.s, he says different things everytime you talk to him.)

I have a feeling he would be going to the library to study on either his type of pokemon he uses or the mythical legends of Sinnoh, but I have a feeling he is searching for a strategy to defeat all the trainers he battles.