What is the whole point of true defense in GC?

I read it as each stack gives 10% less damage per hit, then the stack goes away. Sort of like droid battalion. One hit = 10% less damage. So if you take 9 hits for 10k each, you take 9k damage 9 times, not 1k (90% reduction), then 2k (80%), then 3k (70%), etc.

I didn’t read it as if you have 9 stacks you get 90% less damage on 1 hit. I could see where both interpretations come from though. It’s kind of ambiguous.