Don't bother wasting pots on crisis time. First off crisis time progress carried over from the last time crisis time was around, ie before last guild even, so progress will probably be carried over again.
There are four levels in crisis time and no boss as crisis time currently exists. Perhaps they will add more next time
Crisis time pays out in 3* monsters for the most part
The rare card on every level is epona.
So it's really not worth burning pots unless u really want a bunch of 3* monsters and a few epona