Forum:Six star forms

I have pondered the thought of the six star units ever since the update came that made them possible, to my point there are many units who have acquired new forms event and normal units alike. My ordeal however is that I feel that more deserving units are not confirmed to have planned six star transformations as an example the sinful sisters; they are quite popular units as far as I have seen yet they do not even have six star forms planned as of yet when just about EVERY time a new rare summon unit is confirmed they already have six star forms planned. The point is that most newer units are already anticipated to get six star forms at some point while a lot of the older units still do not even have a six star form awaiting.