Quote Originally Posted by Klepto View Post
I don't know how accurate this is, but this thread seems to have some data on success rates past 9 stars: http://bbs.tynon.com/showthread.php?2130-10-Stars

Granted, this was earlier in beta so things might have changed, but it looks like it costs three Purple Medals for Gold level heroes (ouch, so 100+ gems per attempt at minimum), and 50% chance starting out. Kind of harsh.
After looking at this thread, I pinked a player in a different guild in our realm that has cianna with 9 stars and 2 moons. She said that she had Cianna to 13 stars and had failed all the way back to 9 trying to upgrade her before. Said she was at 30% chance of success right now. So I do think those numbers may be correct. What I am wondering though is if there are no more "Fail Safes" Past level 9 where you start using Purple Medals. If this is the case, then odds get a bit more compunded, as your fail safe in effect is 9 and you are facing 6 more successes with no fail safe.