It's time for another freebie character in the form of Sphica! You'll have to put some time into getting her up to speed though as you'll need to grind all the mats needed to unlock everything.
There seems to be a positive correlation between the ridiculousness of the event name and the amount of grinding you have to do. This time we have to grind up to 50K total event points to unlock those sweet sweet Rainbow Essences.
Bandai like to stress players who try to min/max, so they've thrown in yet another RNG dependent grinding event!