Little fact about Silverwind's beginnings... while Castor knew Atlas from the start, he actually didn't know Quinn until the day they all formed their team. This was because Atlas didn't want it getting out that Quinn was helping him with his heists, which would destroy her future- something he wanted to secure with the money he was making. So Quinn stayed in hiding most of the time, though she'd occasionally go into town to buy a few necessities. Castor vaguely remembered seeing her in the library a few times, but didn't really know anything about her or her connection to Atlas.

When they form their team, he wants to earn her trust and bond with her, partly to ease any awkwardness in the team dynamic, but also because he did genuinely like and care about Atlas and wanted to get to know his family.

Unfortunately, Quinn has... a hard time trusting anybody and doesn't like talking to anyone except Atlas. Not even Atlas's friends... especially not Atlas's friends.

Eventually, Castor does break down Quinn's barriers and becomes a good adult figure for her, the two bond over their common interest in literature and legend and he acts as a mentor for her. She looks at him today and wonders why she ever felt afraid of him, with how goofy he can be.