This card may be intended as a reference to the Behelit, a malefic object from the Berserk manga and anime series. Like the Behelit, the "Full Moon Mirror" is an egg-like object with scrambled facial features on its exterior. Its exterior can be of several colours, including green. Also, both summon the five members from a groupof Evil God-like figures when enough "sacrifices" have been made.
Moreover, said summon is preceded by an eclipse, similarly to a special Berserk event set in a place the artwork resembles.