Thread:Singsweet23/@comment-6697950-20150927042937

Asuna was never officially made a member of the Sleeping Knights. Not even temporarily. Just because she helped them out and befriended them does not make her a guild member.

Additionally, Asuna's nickname 閃光 does not have "lightning" anywhere in it. Nobody but the dub translates it as "lightning" flash, so the "lightning" part is not needed. 