User blog comment:Crimson Storm Mich/Summoner Arc: Weapon/Summon Arts/@comment-26575441-20160915181502/@comment-27997413-20160915231506

however as the summoner arc story continues with new maps and that soon or later we will be able to use 6* and all of those higher ranking units, but it will be a huge pain to grind to get to that level lol