Here's My Suggestion On Getting 9-Tails Chakra Naruto Either Get Lucky On The Seal Treasure Or Collect Fragments As He Becomes Available In Events And Finally Use Spare Fragments From Your 5-Star Characters To Get One Fragment Of Him At A Time. Personally I Like The Idea Of The Skill Breakthrough System It Ups The Challenge Of The Game. Besides Who Doesn't Like A Good Challenge Since It Keeps Things Interesting For The Players Who Play A Game Just To Overcome Its Trials And Tribulations And Say I've Done It When It's All Over?