Hahahaha! Yeah, i saw your last post in the ancient thread that was made last 2016 xD .. i was a bit shocked you dig deep in the forums to see that thread xD .. Well, for me i always refine my frags everytime i have enough fragments to refine that has equivalent of 3k points .. and that's Kabuto and Sasuke fragments since i already 5star-ed them and maxed sasuke's skillbreaks. About the skillbooks and the frags thing they're saying, i don't know what's exactly they mean because for what i understand, you need fragments to get the skillbooks and that skillbooks are the ones you needed to skillbreak the ninjas, right? .. so maybe, go research and ask someone about the possible ninjas that may get skillbreaks in the near future, then save so you'll be ready if that time comes..

I got my Iruka from Refining Fragments, and made him to 3star by Refining Fragments also, and now trying to make him to 4stars by Refining Fragments also :D