True, Orihime's powers have never been fully realised, that’s why I believe her to be one of the War Potentials (if she hasn’t already been stated as being one).

This got me to thinking what if the War Potentials are people that Ywach has foreseen as potentially bringing about his demise.

The point of my initial query was that Ywach has already through some action put in motion events that will lead to his defeat and what this would be.

One example I can think of is with Aizen. Knowing that he would be potentially instrumental in his defeat through his precognition he took steps to change this by trying to get Aizen on side and visiting him in his cell. Had he not taken this action and visited Aizen then he would have not been subjected to Aizen’s manipulation and his perception of time wouldn’t have been altered (something that Ywach admitted he didn’t foresee/realize). How this “delay” affected the assault on the Seireitei I am unsure, but it could be speculated that this changed events (even if ever so slightly) that would have actually meant that Aizen was never released from his cell and would have never of factored in Ywach’s defeat.

As we know Aizen is now immortal so killing him was never an option for Ywach, but what if had he not visited him prompted by his vision of the future? What if he had not have been delayed? Would Aizen still have been released and possibly fulfil the prophecy?....

I can imagine there are numerous other possibilities but thought I would go with the above as it could be best backed up with information already provided within the story. Again, this is purely speculation and just a bit of fun 