Talk:Vergil vs. Sephiroth/@comment-29686583-20161116231711/@comment-2218433-20161127090909

As far as Advent Children is concerned, Kadaj had used the remains of Jenova in a containment unit on himself, which lead to Sephiroth's recreation, since Kadaj had also survived falling into the Lifestream, When Kadaj absorbed Jenova's cells, Sephiroth exerted his power over Jenova to shapeshift Kadaj's body into his own visage, restoring him to life.

It's more or less the fact that Sephiroth can use Jenova's remains and a suitable body to reform him, which is why Sephiroth Post-Final Fantasy VII is the way he is