I'm partial to stories where the love interest is just as capable as the protagonist, and Seria delivers. She's not waiting to be saved; she's often saving Ian from social blunders or using her own resources to investigate. They rescue each other in different ways. That makes them a true dual lead.
Celia, meanwhile, offers a different kind of strength—emotional stability and unwavering friendship. She's the safe harbor. The trio (Ian, Seria, Celia) forms a nice balance of skills: foresight, social/political power, and emotional grounding. They're a team, even if the official mission is just Ian and Seria's.