Maybe not Bastien, but Esperanza and Earnest? Esperanza has an intimidating aura; a conference that she may have drawn from her presumed-dead family line? And the way Earnest is always inside the castle, always on the edge - is that only because of his social position? Maybe it's his responsibility for the truth that keeps him alarmed all the time?
What if Lukas got involved with Esperanza? What if Esperanza is the source of Lukas' new found knowledge? In order to search for the truth, he may have gotten too close to her. What if their relationship ran deeper than what Lukas had with Bastien? Remember Ali said that he grew up with Bastien, Esperanza, and they were once very close. What if Lukas' involvement, or maybe even affection for Esperanza is why they fell apart?