357: This could refer to a caliber of ammunition, a number in a sequence, or potentially something else entirely. Without more context, it's hard to say what you're specifically referring to here.
“Don’t do it, Kael,” she said. “Don’t trade yourself for me.” 357 missax my sister the princess athena fleu portable
flew portable: This seems to suggest something that can move or has moved ("flew" implies flight) and is portable. 357 : This could refer to a caliber