Originally Posted by
Flocci
For anyone worrying about the rng part of the event and the min-avg-max number of crystals, I will copy my post from /jp/ over here.
On a side note, this is all assuming you never mess anything up, so it's probably still a good idea to have a bit of a safety net, in case you fail a map. If you're worried you can't clear the final mission, but can clear the 2nd to last map, I would roughly estimate that you need something like 2-4 ish more crystals. If you can't clear that one either, you should probably give up on maxing her unless you're willing to spend around 50 crystals for it, but getting the black one is still within reach with a reasonable number of crystals.
Also, as a little bonus calculation: If all the little particles in the entire (observable) universe had an Aigis account for the event, you would expect around 100 of them to pay the "max" amount.