If you control no monsters, or only Xyz Monsters: You can Special Summon this card from your hand, and if you do, Special Summon 1 "Exosister Elis" from your Deck. You cannot Special Summon monsters the turn you activate this effect, except "Exosister" monsters. If a card(s) moves out of either GY (except during the Damage Step): You can Special Summon from your Extra Deck, 1 "Exosister" Xyz Monster, using this face-up card you control as material. (This is treated as an Xyz Summon.) You can only use each effect of "Exosister Martha" once per turn.