Board Thread:Questions and Answers/@comment-10797017-20130627100621/@comment-6904925-20130824071255

I think the other 3 are:

Kisuke; because of his incredible intellect he could give information on how to counter the Quincies as in 499, he told them the weakness of Blut, on how the Blut can't be used for both offense and defense at the same time. Plus at the moment he is probably working on a way to negate the Quincies stealing the bankai's with the medallion he got from Quilige in 544.

Perhaps Shunsui; the moment he goes to see Ichigo friends, the Quincies invade the Soul Society.

The last one could be Grimmjow; because he is a former Espada, and I don't think the Quincies can steal an Arrancar's Resurrección, therefore he is able to fight against a Sternritter with no worries of his powers being stolen.