It's the Chevalier's most heavily guarded treasure hall that is filled with high-graded spells and incantations. Aside from the Marquis, the other three children…. Altron, Harrison, and Felicity were the ones who were allowed to have access to enter the hall.
The Marchioness doesn't have the privilege, even though she is the legal wife of the Marquis because there were rules that only allowed the direct family bloodline of the Chevaliers.
Eclipse should have access to the Hall of Legacy even though he is a half-blood noble, but his father's blood still runs through his veins. However, they denied him because of his birth mother's commoner status.
'As if I care about that right now. Before, it was a big deal for me but now that I am back and thinking about it, I couldn't help but feel foolish. Why am I so obsessing about my father's acknowledgment, anyway?'