Board Thread:General Discussion/@comment-96.224.225.28-20141201045828/@comment-3250527-20150130040059

First off...

you're* rude.

Besides, it has been stated in the forum descriptions that the S,R,&G Board is the board only for such "speculation, rumor, and gossip".

Gsi is serious about "speculations" popping up where they shouldn't be ( as with a certain dispute about a tattoo that resembled the emblem of a certain killing guild ), because this is a post in the question and answers, where one asking a question would take any reasonable answer that would make a certain item OP.

On a second note, since that the Mother's Rosario arc is a considerable time after the events of Calibur, Asuna was aware of Kirito's skills, and Reki would have stated (in Asuna's POV) that Kirito would be bisecting weapons left and right. Most of us who have read the Light Novel noticed how precise Reki has written SAO—he leaves nothing out.

That being said, Excaliber may as well not have a hidden ability. No one will know until Kirito uses the said sword in battle, and we get a glimpse of his thoughts through his POV.