I failed at 80% then failed at 70% which is very frustrating, but I would rather fail than get another magic attack on a physical hero. On evony I would fail stars with a 100% success rate listed so this doesn't surpise me at all. I'm just under 1 million power and top ranked in arena for my realm yet my main hero has 1 star, i think i've gone through about 25 medals and never been passed level 3.