Usage of Holy Crystal??

[GDBigBangSeoul]

How can I use Holy Crystal??

[Livestock]

You use holy crystals to upgrade your angel every 10 lvls (except for lunaria who requires holy crystals after level 30+).

[GDBigBangSeoul]

so every 10 levels cost some Holy Crystal??

[R2352025]

at lv30 angel u need them for upgrade lv3 holy stones
at lv40 angel u need lv4 holy stone,

lv1-2 holy stones are just junk u syth to lv3