Sean and Kitty were old acquaintances of Yan Fei, but not under the identity of Yan Fei, rather he befriended them as the Destroyer.
Back then, Yan Fei went to the Louvre Museum in France to steal Drone Upgrade Essential Items, but he encountered the Blue Fox Thieves Group, who were also aiming to steal treasures from the Louvre. Sean and Kitty were core members of this thieves group. Yet at that time, they were betrayed by an undercover companion, leading to their mission's failure. At the critical moment, Kitty proactively reached out to Yan Fei, who also needed help. The two of them worked together harmoniously and not only did Yan Fei obtain the Upgrade Essential Items, but he also helped Kitty rescue Sean.
