Board Thread:Questions and Answers/@comment-10797017-20130627100621/@comment-11477779-20130705212555

As to the Royal Guard being a special war potential, if that's the case I think it would be all five as a group and not any particular member. Yhwach's attack on the Soul Society did seem to have the purpose of drawing out the Royal Guard indicating their importance to him, either as an obstacle to be removed or as something he can turn to his own advantage. Remains to be seen what the purpose is.