The group begins to encounter Sephiroth during their journey, who continuously appears and disappears after taunting Cloud and sending Jenova-esque monsters after him. Finding him at a Cetra temple, Sephiroth reveals his intentions to use the Black Materia to summon "Meteor", a spell that will hit the Planet with a devastating impact. Sephiroth will absorb the Lifestream as it attempts to heal the wound, becoming a god-like being. The party retrieves the Black Materia, but Sephiroth manipulates Cloud into surrendering it. Aerith departs alone to stop Sephiroth, following him to an abandoned Cetra city. During Aerith's prayer to the Planet for help, Sephiroth attempts to force Cloud to kill her; failing, he kills her himself before fleeing and leaving the Black Materia behind. The party then learns that Jenova is not a Cetra as once thought. Rather, it is a hostile alien lifeform whose remains were unearthed by Shinra scientists decades earlier; at Nibelheim, Jenova's cells were used to create Sephiroth.