Zefraxa, Flame Beast of the Nekroz
[ Pendulum Effect ] 
You cannot Pendulum Summon monsters, except "Nekroz" and "Zefra" monsters. This effect cannot be negated.
[ Monster Effect ] 
While this card is in your hand or Graveyard, if a face-up "Nekroz" or "Zefra" card(s), except "Zefraxa, Flame Beast of the Nekroz", is destroyed by battle or card effect while in your Monster Zone or Pendulum Zone: You can Special Summon this card. You can only use this effect of "Zefraxa, Flame Beast of the Nekroz" once per turn.