Sorry to keep asking stuff, friend keeps finding ways to break his characters
So defensive stance, his question is it says "When yoou use foresight, apply +1 defense to your defense results." His question is if he uses foresight multiple times against one attack will he then have stacked the defensive results? IE he uses it 5 times in one defense does it give him +5 defense on top of his roll? Or is this like x-wing where you cant reroll dice that have already been rerolled?

From Rules Reference p.5, Under "Steps of an Attack - Rerolls":

- Each die may be rerolled only once per attack regardless of who is rerolling the die.

So his followup question to this was, if he was rolling two defense dice would he be able to reroll both those dice by using forsight twice?

Foresight can only be used to reroll one die during an attack. In the RRG page 2 under Abilities the first bullet says: "If an ability is 'used' it can be triggered multiple times each round, but it can only be triggered once per timing instance ."

It says use while defending so it can be used once while Diala is defending an attack.