If you hit a target(mob, player) with the first style in a style chain the next style in the chain will be saved and you are able to use it whenever reflex attack procs. You can have reflex attack proc multiple times on the same or different targets or wait a few mins and the next style in the chain will still be saved and available to be used when reflex attack procs and you decide to use the style.
Example that happened today:
I parry and hit a hero with my "Comeback" style.
He slams me for 9sec.
Reflex attack procs multiple times during the stun when he hits me.
Just before the 9sec stun ended my reflex attack hit the hero and when the slam duration was over I was instantly able to hit my "Frosty Gaze" 7sec stun on the hero even after I was stunned for 9seconds.
I was not recording when it happend in real fights but here is a video to show the bug:
https://www.youtube.com/watch?v=pslX5LJu4RA
