She doesn't know what to think of Reiji. Serena has been confused ever since she's escaped Fusion, but he perplexes her the most. From gossip from Sakaki and co, apparently he confuses everyone. However she thinks he confuses her for very different reasons.
She's no better at reading him than anyone else, but he seems to act slightly less like a stoic mastermind who has the next five years planned out around her. Of course it is not like they've had heart-to-heart talks long into the night. He is still a quiet and quite intelligent sixteen year-old. But he does tend to seem like talking to her, or maybe "at her" is the better way to put it. That night after Hiragi disappeared, she had stayed with him, having no where else to go. While his servant had been preparing a room for her, they had both been sitting in a waiting room of sorts, and the silence was suffocating. It was a risky move, but Serena had decided even her horrible attempts at small talk was better than nothing.
"If you wanted me to be a Lancer, why did you let me run around Standard?" It was an awkward question even for her. Still he answered thoroughly as if explaining a chemical reaction in that steady voice of his.
"You might not remember, but three years ago, we met in Fusion." He went on to recall that memory, one she also shared, but she had found no reason to tell him so. And moreover he went on to discuss future plans and such with her as an equal. He didn't ask for her suggestion or anything like that or seem unsure in anything. However he didn't seemed to be talking down and commanding her like his father often did. He even reveled classified information like Hiragi's whereabouts before anyone else knew what to do.
She was still unsure what it all meant, but she found herself endeared to him. He made the most sense out of everyone here, reminding her of the good sides of Fusion, it's discipline and emphasis on staying logical (even if she, herself, didn't always embody those traits).
When they crossed over dimensions, she couldn't help but notice he was absent from their group. It didn't affect her much til they ended up in prison of all places. For some reason she was separated and left alone (again kept in a gilded cage like she couldn't hold her own), and that gave her plenty of time to wonder how far off Reiji's beautifully constructed plan had veered. As expected she couldn't help but wonder where he was and eventually her mind started coming up with the craziest ideas. Academia trained her to expect and prepare for the worst case scenario, so it was quite frustrating having to sit around there, as her mind rattled off a thousand ways the Lancer's could have fallen apart while she was absent.
When they finally all reunited, and she saw Reira had gone off with Reiji, she finally let out a sigh of relief.
"So you were safe," Serena felt like an idiot for muttering those words out loud later, but in that moment she had come to an important realization.
She wasn't quite sure who Reiji exactly was, but she felt like she could trust him and that they might be able to get along amicably. It wasn't much, yet it still topped any or her relationships in Fusion.
He might have the potential to be a friend.
A.N. Some of my followers might have seen my reaction to this ship (a lot of ? and screaming for fear of the unknown), it came out of nowhere and I decided to just try to write something out to help me understand my feelings toward them. (I thought finding content for other ships was bad, wow).