Ghost ; Just run the e-8 stage to let it spawn SG, you will get tons of blue macaron in no time.
In my case the system really spawn a lot of SG during I running event map, should help.

Pochulaca... (don't know how to spell her name) have to be develop first.
But at least she can dodge that usefull for swan-boat stage.

About crystal... I need it for wipe out amps in shop and spare for next shop reset.
Already have 3.8k in stock so... maybe 4k crystal will be possible...