Well, they probably had a name for the aura guardian before, but Mark hadn't known it before now... better late than never! "He's been pretty sensitive talking about it," Especially when you were being terribly insensitive when talking about it, Mark, you unintentional buffoon, "but she was the only Lucario trainer we know of around Ternai, which is where Mina found the little guy, and he definiely had a trainer at some point. Do you know what kind of supplies she was looking for? And is there anything weird or special about the mountains north of Ternai?" Maybe she'd been looking for something up there, and that would be the best place to start looking if Riolu couldn't tell them where to go.