He remains unresponsive to the sardonic remarks coming his way. He's done jobs for an organization of magi while using almost no magecraft himself. While many individual members spend their last days fearing his appearance beyond any nightmare, the ones who contract him tend to think themselves above the Clock Tower's game, unable to face retribution when they inevitably cross a line, and wielding a personality to fit those beliefs. They are rarely right. It is this fact, along with his ability to block emotions, that has allowed Kiritsugu to never really care about how he's talked to.

Eye contact is broken by the other man first, and he is more than willing to accommodate, looking at the crowd ahead. Kiritsugu does not appreciate having another party be aware of his identity without him doing the same. Puts them at an advantage. While he normally wouldn't expect to have the answer just handed to him, that was before the extended surprise that this entire conversation has been.

"Association?"