Board Thread:Questions and Answers/@comment-10797017-20130627100621/@comment-11477779-20130705122748

We only need to speculate on the remaining 3 (or 2 if Aizen was truly one of the original 5). Known: 1) Kenpachi Zaraki 2) Ichigo

I agree with the majority that NO arrancar is a special war power. Likewise I don't think Isshin or Ryūken are either. Uryū could be one. He's definitely pivotal to Yhwach's plans in some way to the point he feels the need to control Uryū. Kisuke or Mayuri are possibilities based on their technical abilities to find ways to counter the Vandenreich potentially. Mayuri is definitely the more scorched-earth type and most likely to attempt to wipe them out entirely. The Soul King might be from the standpoint of he/it never getting directly involved (deus ex machina anyone?) but it doesn't feel right. Chad... no. Sorry Chad. Orihime is a possibility. Her ability to reject phenomena is powerful but during the arrancar arc she was just a red herring. Unfortunately (or fortunate, depending on how you look at it!) it seems to be too early to tell.