The void monster Greza is one of the most special monsters among the many monsters that exist. Because Greza doesn't even "exist" exactly, it's nothingness! Greza, who appears in the world of "Ultraman X", falls into despair in search of the great power of monsters! In the world of "Ultraman Z", Zet and Geed greet Greza, but even the two major Ultramans can't attack at all! What to do Ultraman! ??
