User blog comment:Mich, Michele & Kuhla/Future Units Preview/@comment-27850788-20160309010718/@comment-27038814-20160309233214

Yeah, and here is a major tip (I made this mistake since I was too unsure and appearently rates were good, but only because the other players had like 500 gems to spend). DON'T SPEND YOUR GEMS WHEN THEY FIRST COME OUT. Spend it when ALL 6 are showcased in the summon. You have a great chance then.