Crystal Cave is the Game Mode which rewards crystals upon completion, which are used to awaken mercenaries.
Crystal Cave is split based on class type (eg. Warrior, Magician, etc.) and affects not only which day of the week it appears on, but also what class types can be taken in to challenge the Crystal Cave of that day. Additionally, each cave type is split into 5 different stages with increasing difficulty and rewards.
The schedule is as follows (based on JST):
|Chaos (All Available)||Magician||Warrior||Defender||Magician||Warrior||Defender|
The restrictions for each Cave class type are:
|Class Type Cave||Restriction|
|Magician||Warrior / Supporter Only|
|Warrior||Defender / Supporter Only|
|Defender||Magician / Supporter Only|
|Stage 1||Low Defender Crystals|
|Stage 2||Low/Medium Defender Crystals|
|Stage 3||Medium Defender Crystals|
|Stage 4||Medium/High Defender Crystals|
|Stage 5||High Defender Crystals|